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WORKS OF JOHN S. REID 



PUBLISHED BY 



JOHN WILEY & SONS. 



A Crurse in Mechanical Drawing. 

8vo. viii + i86 pages, i68 figures. Cloth, $2.00. 



Mechanical Drawing and Elementary Machine 
Design. 

By John S. Reid, Professor of ^Mechanical Draw- 
ing, Annour Institute of Technology, and David 
Reid, formerly Instructor in Mechanical Drawing, 
Sibley College, Cornell University. 8vo.xii-f 439 
pages, 301 figures. Clotti, $3.00 



A COURSE IN 



MECHANICAL DRAWING. 



BY 



JOHN S. REID, 

Instructor in Mechanical Drawing and Designing,^ 

Sibley College, Cornell University ^ 

Ithaca, N. V, 



THIRD EDITION, REVISED AND ENLARGED. 
FIRST THOUSAND. 



NEW YORK. 

JOHN WILEY & SONS. 

London: CHAPMAN c^^ MALL, Limited. 
lOOS. 



^"-^ 






LIBRARY of CONGRESS^ 
(wo Cooies Keceive(< | 

OCT 2 i«^a| 



COP 



Copyright, 1898, 1908, 

BY 

JOHN S. RE ID. 



iSobprt iBrutntnonib aniJ Olompang 
2fwti Sork 



PREFACE TO THE THIRH EDITION. 



To MEET the demands of high schools, manual training high 
schools, university preparatory schools, technical colleges, and 
evening classes, it has been found necessary to add to ''A Course 
in Mechanical Drawing" a concrete set of problems covering the 
full requirements in mechanical drawing for entrance to the more 
advanced classes in machine drawing, elementary machine de- 
sign, and architectural drawing. The minimum time allowed 
in a definite number of working hours for the finishing of each 
plate, as introduced in this edition, is a new feature, and will be 
much appreciated by Instructors when determining the amount 
of work to require from their students in a given term. The 
time allowed for the different plates has been carefully deter- 
mined by taking note of the actual number of hours taken by 
large numbers of students working on the same plates, under the 
same conditions, and a conservative average taken, so that any 
young man of fair intelligence and with an honest endeavor may 
finish any of the plates in the time given. 

The Course in Lettering, which has also been added to this 
edition, will be found to be of great practical benefit to students 
in all kinds of engineering drafting, and will be seen to embrace 

iii 



iv PREFACE. 



n 



the most approved practice in drafting room methods at the 
present time. 

The report on the "Present Practice in Drafting Room 
Methods," which will be found at the end of the book, is also 
new and will interest Instructors and enable them to adopt a 
system in their drawing courses that may closely approximate the 
best practice in the leading and most progressive drafting rooms 
in the United States. 

The thanks of the author are due and are most cordially 

extended to those who have used this book in the past and have 

encouraged and assisted him by gracious words and timely 

suggestions. 

John S. Reid. 

Armour Institute of Technology, 
Chicago, III., September, 1908. 



PREFACE. 



In the course of a large experience as an instructor in 
drawing and designing, tlie author of this work has often been 
called upon to teach the elements of mechanical drawing to 
students in marine, electrical, railway, and mechanical engi- 
neering. Having tried and failed to find a book on the sub- 
ject that was entirely suitable for his use as a text-book, he 
has found it necessary to prepare the present work. 

This course contains, in the author's judgment, a com- 
plete and concise statement, accompanied by examples, of 
the essential principles of mechanical drawing — all that any 
young man of ordinary intelligence needs to master, by care- 
ful study, the more advanced problems met with in machine 
construction and design. Such works as the author has tried, 
although most excellent from certain standpoints, were cither 
incomplete in some of the divisions of the subject or too vohi- 
minous and elementary in the treatment of details. 

The author does not imagine this work is perfect, but he 
believes that it comes nearer what is needed in teaching tlic 
elements of mechanical drawing in tcclinical schools, high 
schools, evening drawing schools, and colleges than any work 
he has examined. 

The chapter on Conventions will be appreciated by students 



Vi PREFA CE. 

when called upon to execute working drawings in practical 

work. The methods described are considered by the author 

to be those which have met with general approval by the 

experienced American draftsmen of the present time. 

My acknowledgments are due to E. C. Cleaves, professor 

of drawing, Sibley College, Cornell University, for reading 

the manuscript and making some valuable suggestions. 

The AuthoRo 

April I, 1898. 



CONTENTS. 



INTRODUCTION. 

PAGE 

The Complete Outfit, Illustrated i 

CHAPTER I. 

Instruments 7 

Use of Instruments 7 

Pencil 7 

Drawing Pen 9 

Triangles 11 

T Square n 

Drawing Board ii 

Sibley College Scale 12 

Scale Guard 12 

Compasses 13 

Dividers or Spacers 13 

Spring Bows 14 

Irregular Curves 14 

Protractor 14 

CHAPTER II. 

Geometrical Drawing 16 

CHAPTER III. 

Conventions 56 

CHAPTER IV. 

Lettering and Figuring 64 

vii 



^^^^ cox TEXTS. 

CHAPTER V. 

Orthographic Projection 

Shade Lines, Shades, and Shadovrs " '''^ 

Conventions "^°^ 

Shades [[[ ^°4 

Shadows yy^..][ ^"^ 

Isomelrical Drawing ■"" ^ ^ 

Working Drawings ^^" 

I2() 



Problems ix Mechanical Drawing (Course I) . 



OD 



Makix\g Practical Working Drawings 

165 



MECHANICAL DRAWING. 



INTRODUCTION. 

A NEED has been felt by instructors and students, especially 
in technical courses, for a text-book that would illustrate the 
fundamental principles of mechanical drawing in such a prac- 
tical, lucid, direct and progressive way as to enable the 
instructor to teach, and the student to acquire, the greatest 
number of the essential principles involved, and the ability to 
apply them, in a draftsman-like manner, in the shortest space 
of time. 

With this in mind, the present work has been prepared 
from the experience of the writer, a practical draftsman and 
teacher for over fifteen years. 

THE COMPLETE OUTFIT. 

The outfit for students in mechanical and machine drawing 
is as follows : 

(i) The Drawing-board for academy and freshman work is 
i6'''X2i''xy, the same as that used for free-hand (Irawinii 
The material should be soft pine and constructed as shown b\ 
Fig. I. 

(2) I Scribbling Pencil with rubber lip. 



MECHA NIC A L DRA II 'I NO. 



(3) Pencils, one 6H and one 4H Koh-i-noor or Faber. 

(4) The T-Square; a plain pearwood T-square with a fixed 
head is all that is necessary. Length 21''. 




Fig. I. 



(5) Instruments. ''Pocket Book" Set, shown by Fig. 2^ 
recommended as a first-class medium-priced set of instruments. 
It contains 




Fig. 2. 



A Compass, k^V' long, with fixed needle-point, pencil, pen 
and lengthening bar; a Spring Bow Pencil, 3'' long; a 
Spring Bow Pen, 3'' long; a Spring Bo^v Spacer, 3''' long; 



INTRODUCTION. 3 

2 Drawing-pens, medium and small, i Hair-spring Divider, 
5'' long; a nickel-plated box with leads. 




Fig. 4. 




Fig. 5. 

(6) A Triangular Boxwood Scale graduated as follows: 
4" and 2-, 3'' and Iy^ V and V', ^'' and r, A" and j^/'. 

(7) I Triangle 30^X60°, celluloid, 10^' long. Fig. 4. 



45 > 



7 



// (< 



MECHAXICAL DRAWIXG. 

(8) I Irilegulah CmvE. Xo. 13. Fig. 5. 

(9) E:mxry P£^XIL Pointer. 

(10 j IxK. black waterproof. Fig. 7. 

(11) IxK Ee_\5£Pv. Faber's T\-pewriter. Xo. 104. 

(12; Pencil Eraser, ''Emerald*' Xo. 211. Fig. 9. 




Q ^ 


-J 


S 5 "'•111 


2 ? =»' 


^ i 


DC 


u 


a 


UJ 


III 



Fig. 7. 



Fig. S. 



F;:-. 0. 

(13) Sponge Rubber or Cube or ''Artgum. " Figs. 10, 11. 

(14) Tacks, a small carton of i oz. copper tacks, and i doz» 
small thumb tacks. 



1 ^/ 

16 • 



(15) Arx.\nsa5 Oie Stone. 2"xJ"Xt 

(16) Protractor German silver, about 5'' diam. Fig. 12. 

(17) SC-ALE GU-ARD, " " Fig. I3. 



INTRODUCTION, 



(i8) 2 sheets of "Cream" Drawing Paper. 1:5'' x 20". 

{19) 2 " '' Imperial Tracing Cloth. i5'''X2o". 

{20) I Cross-section Pad. S^'Xio''. 

{21) I Scribbling Pad. 




Fig. 10. 




Fig. II. 




Fig. 



12. 



l^i.l.i.-l,i,hulh,l,i,h,.i.,,l 
Fig. 13. 



(22) T Erasing Shield, nickel plated. 

(23) 2 Lettering Pens, ''Gillott" No. 303. 

(24) 2 *' *' *'Ball Point," No. 506. 

(25) 2 '' *' '* *' No. 516. 

(26) I Two-foot Rut,e 



4 



CHAPTER I. 
INSTRUMENTS. 

It is a common belief among students that any kind of 
cheap instrument will do with which to learn mechanical 
drawing, and not until they have acquired the proper use of 
the instruments should they spend money in buying a first- 
class set. This is one of the greatest mistakes that can be 
made. Many a student has been discouraged and disgusted 
because, try as he ^vould, he could not make a good drawing, 
using a set of instruments with which it would be difficult for 
even an experienced draftsman to make a creditable showing. 

If it is necessary to economize in this direction it is better 
and easier to get along with a fewer number, and have them 
of the best, than \t is to have an elaborate outfit of question- 
able quality. 

The instruiryznts shown in Fig. 2 are well made of a moderate 
price, and with care and attention wiU give good satisfaction for 
a long time, 

USE OF INSTRUMENTS. 

7Vze Pencil. — Designs of all kinds are usually worked out 
in pencil first, and if to be finished and kept they are inked in 
and sometimes colored and shaded ; but if the drawing is only 
to be finished in pencil, then all the lines except construction, 
center, and dimension lines should be made broad and dark, 

6 



INSTRUMENTS. 7 

SO that the drawing will stand out clear and distinct. It will 
be noticed that this calls for two kinds of pencil-lines, the 
first a thin, even line made with a hard, fine-grained lead- 
pencil, not less than 6H (either Koh-i-noor or Faber's), and 
sharpened to a knife-edge in the following manner: The lead 
should be carefully bared of the wood with a knife for about 
y , and the wood neatly tapered back from that point ; then 
lay the lead upon the emery-paper sharpener illustrated in the 
outfit, and carefully rub to and fro until the pencil assumes a 
long taper from the wood to the point ; now turn it over and 
do the same with the other side, using toward the last a 
slightly oscillating motion on both sides until the point has 
assumed a sharp, thin, knife-edge endwise and an elliptical 
contour the other way. 

This point should then be polished on a piece of scrap 
drawing-paper until the rough burr left by the emcry-papci is 
removed, leaving a smooth, keen, ideal pencil-point for draw- 
ing straight lines. 

With such a point but little pressure is required in the 
hands of the draftsman to draw the most desirable line, one 
that can be easily erased when necessary and inked in to 
much better advantage than if the line had been made with a 
blunt point, because, when the pencil-point is blunt the incli- 
nation is to press hard upon it when drawing a line. This 
forms a groove in the paper which makes it very difficult to 
draw an even inked line. 

The second kind of a pencil-line is the broad line, as 
explained above; it should be drawn with a somewhat soft cm 
pencil, say 4H, and a thicker pcMnt. 

All lines not necessary to explain the drawing shouKl \>c 



:8 



MECHANICAL DRAWING 



•erased before inking or broadening the pencil-lines, so as to 
make a minimum of erasing and cleaning after the drawing is 
-finished. 

When drawing pencil-lines, the pencil should be held in a 
plane passing through the edge of the T-square perpen- 
dicular to the plane of the paper and making an angle with 
the plane of the paper equal to about 60"". 

Lines should always be drawn from left to right. A soft 
■conical-pointed pencil should be used for lettering, figuring, 
and all free-hand work. 

TJii Draiuing-ptu. — The best form, in the writer's opinion, 
is that shown in Fig. 14. The spring on the upper blade 




Fig. 14. 




Fig. i^. 



spreads the blades sufficiently apart to allow for thorough 
cleaning and sharpening. The hinged blade is therefore 
unnecessary. The pen should be held m a plane passing 
through the edge of the T-square at right angles to the plane 
of the paper, and making an angle with the plane of the 
paper ranging from 60° to 90°. 



INSTRUMENTS. g 

The best of drawing-pens v/ill in time wear dull on the 
point, and until the student has learned from a competent 
teacher how to sharpen his pens it would be better to have 
them sharpened by the manufacturer. 

It is difficult to explain the method of sharpening a draw- 
ing-pen. 

If one blade has worn shorter than the other, the blades 
should be brought together by means of the thumb-screw, and 
placing the pen in an upright position draw the point to and 
fro on the oil-stone in a plane perpendicular to it, raising and 
lowering the handle of the pen at the same time, to give the 
proper curve to the point. The Arkansas oil-stones (No. 15 
of " The Complete Outfit ") are best for this purpose. 

The blades should next be opened slightly, and holding 
the pen in the right hand in a nearly horizontal position, place 
the lower blade on the stone and move it quickly to and fro, 
slightly turning the pen with the fingers and elevating the 
handle a little at the end of each stroke. Having ground the 
lower blade a little, turn the pen completely over and grind 
the upper blade in a similar manner for about the same length 
of time ; then clean the blades and examine the extreme 
points, and if there are still bright spots to be seen continue 
the grinding until they entirely disappear, and finish the 
sharpening by polishing on a piece of smooth leather. 

The blades should not be too sharp, or they will cut the 
paper. The grinding should be continued only as long as the 
bright spots show on the points of the blades. 

When inking, the pen should be held in about the same 
position as described for holding the pencil. I\Ian\' drafts- 
men hold the pen vertically. The [)osition may bo \'aricd 



lO MECHANICAL DRAWING. 

with good results as the pen wears. Lines made with the pen 
should oniv be drawn from left to ri2[ht. 



THE TRIANGLES. 

The triangles shown at Fig. 4 (in " The Complete Outfit ") 
are 10" and /' long respectively, and are made of transparent 
celluloid. The black rubber triangles sometimes used are but 
very little cheaper (about 10 cents) and soon become dirty 
when in use ; the rubber is brittle and more easily broken than 
the celluloid. 

Angles of 15°, 75°, 30°, 45°, 60°, and 90° can readily be 
drawn with the triangles and T-square. Lines parallel to 
oblique lines on the drawing can be drawn with the triangles 
by placing the edge representing the height of one of them 
so as to coincide with the given line, then place the edge rep- 
resenting the hypotenuse of the other against the corre- 
sponding edge of the first, and by sliding the upper on the 
lower when holding the lower firmly with the left hand any 
number of lines may be drawn parallel to the given line. 

The methods of drawing perpendicular lines and making 
angles with other lines within the scope of the triangles and T- 
square are so evident that further explanation is unnecessary. 

THE T-SQUARE. 
The use of the T-square is very simple, and is accom- 
plished by holding the head firmly with the left hand against 
the left-hand end of the drawing-board, leaving the right 
hand free to use the pen or pencil in drawing the required 
lines. 



IN ST RUM EN IS. II 

THE DRAWING-BOARD. 

If the left-hand edge of the drawing-board is straight and 
oven and the paper is tacked down square with that edge and 
[he T-square, then horizontal lines parallel to the upper edge 
of the paper and perpendicular to the left-hand edge may be 
drawn with the T-square, and lines perpendicular to these 
can be made by means of the triangles, or set squares, as they 
are sometimes called. 

THE TRIANGULAR SCALE. 

This scale, illustrated in Fig. 3 (in ''The Complete Out- 
fit"), was arranged to suit the needs of the students in machine 
drawing. It is triangular and made of boxwood. The six 
edges are graduated as follows; y^^' or full size, -^-(^" , i" 
and I" == I ft., \" and k" = i ft., ^" and i^" = i ft., and 
4'' and 2" = I ft. 

Drawings of very small objects are generally shown en- 
larged — e.g., if it is determined to make a drawing twice the 
full size of an object, then where the object measures one inch 
the drawing would be made 2'\ etc. 

Larger objects or small machine parts are often drawn full 
size — i.e., the same size as the object really is — and the draw- 
ing is said to be made to the scale of full size. 

Large machines and large details are usually made to a 
reduced scale — e.g., if a drawing is to be made to the scale of 
2" — I ft., then 2" measured by the standard rule would be 
divided into 12 equal parts and each part would represent i". 
See Fig. 81^. 



II 



12 



M EC 11 A NICAL DRA WING. 



THE SCALE GUARD. 

This instrument is shown in No. 17 (in "The Complete 
Outfit "). It is employed to prevent the scale from turning, 
so that the draftsman can use it without having to look for 
the particular edge he needs every time he wants to lay off 
a measurement. 

THE COMPASSES. 

When about to draw a circle or an arc of a circle, take 
hold of the compass at the joint with the thumb and two first 
fingers, guide the needle-point into the center and set the 
pencil or pen leg to the required radius, then move the thumb 
and forefinger up to the small handle provided at the top of 
the instrument, and beginning at the lowest point draw the 
line clockwise. The weight of the compass will be the only 
down pressure required. 




Fig. 16. 

The sharpening of the lead for the compasses is a very im- 
portant matter, and cannot be emphasized too much. Before 
commencing a drawing it pays well to take time to properly 
sharpen the pencil and the lead for compasses and to keep 
them always in good condition. 

The directions for sharpening the compass leads are the 
same as has already been given for the sharpening of the 
traight-line pencil. 



INSTRUMENTS. 



13 



THE DIVIDERS OR SPACERS. 

This instrument should be held in the same manner as de- 
scribed for the compass. It is very useful in laying off equal 
distances on straight lines or circles. To divide a given line 
into any number of equal parts with the dividers, say 12, it 
is best to divide the line into three or four parts first, say 4, 
and then when one of these parts has been subdivided accu- 
rately into three equal parts, it will be a simple matter to 
step off these latter divisions on the remaining three-fourths 



(PilSii 




Fig. 17. 

of the given line. Care should be taken not to make holes in 
the paper with the spacers, as it is difficult to ink over them 
without blotting. 



THE SPRING BOWS. 

These instruments arc valuable for drawing the small cir- 
cles and arcs of circles. It is very important that all the 



14 MECHANICAL DRAWING. 

small arcs, such as fillets, round corners, etc., should be care- 
fully pencilled in before beginning to ink a drawing. ]\Iany 
good drawings are spoiled because of the bad joints between 
small arcs and straight lines. 

When commencing to ink a drawing, all small arcs and 
small circles should be inked first, then the larger arcs and 
circles, and the straight lines last. This is best, because it is 
much easier to know where to stop the arc line, and to draw 
the straight line tangent to it, than z'icc versa. 

IRREGULAR CURVES. 

The irregular curve shown in Fig. 5 is useful for drawl- 
ing irregular curves through points that have already been 
found by construction, such as ellipses, c}cloids epicyloids, etc., 
as in the cases of gear-teeth, cam outlines, rotary pump wheels, 
etc. 

When using these curves, that curve should be selected 
that will coincide with the greatest number of points on the 
line required. 

THE PROTRACTOR. 

This instrument is for measurina- and constructine ansfles. 
It is shown in Fig. 12. It is used as follows when measuring 
an angle: Place the lower straight edge on the straight line 
which forms one of the sides of the angle, with the nick 
exactly on the point of the angle to be measured. Then the 
number of degrees contained in the angle may be read from 
the left, clockwise. 

In constructing an angle, place the nick at the point from 
which it is desired to draw the angle, and on the outer circum- 



i 



I.XSTRUMENTS. 15 

ference of the protractor, find the figure corresponding to the 
number of degrees in the required angle, and mark a point on 
the paper as close as possible to the figure on the protractor; 
after removing the protractor, draw a line through this point 
to the nick, which w^ill give the required angle. 



CHAPTER II. 

GEOMETRICAL DRAWING. 

The following problems are given to serve a double pur- 
pose : to teach the use of drawing instruments, and to point 
out those problems in practical geometr}- that are most useful 
in mechanical drawing, and to impress them upon the mind of 
the student so that he may readily apply them in practice. 

The drawing-paper for this work should be divided tem- 
porarily, with light pencil-lines, into as many squares and rec- 
tangles as may be directed by the instructor, and the drawings 
made as large as the size of the squares will permit. The 
average size of the squares should be not less than 4". When 
a sheet of drawings is finished these boundary lines may be 
erased. 

It will be noticed in the illustrations of this chapter that 
all construction lines are made very narrow, and given and 
required lines quite broad. This is sufficient to distinguish 
them, and employs less time than would be necessary if the 
construction lines were made broken, as is often the case. 

If time will permit, it is advisable to ink in some of these 

drawings toward the last. In that event, the given lines may 

be red, the construction lines blue, and the required lines 

black. 

But even when inked in in black, the broad and narrow 

16 



GEO ME 7 RICA L DRA WIIS G. I 7 

lines would serve the purpose very well without the use of col- 
ored inks. 

The principal thing to be aimed at in making these draw- 
ings is accuracy of construction. All dimensions should be 
laid off carefully, correctly, and quickly. Straight lines join- 
ing arcs should be exactly tangent, so that the joints cannot 
be noticed. It is the little things like these that make or mar 
a drawing, and if attended to or neglected they will make or 
mar the draftsman. The constant endeavor of the student 
should be to make every drawing he begins more accurate, 
quicker and better in every way than the preceding one. 

A drawing should never be handed in as finished until the 
student is perfectly sure that he cannot improve it in any way 
whatever, for the act of handing in a drawing is the same, or 
should be the same, as saying This is the best that I can do; 
I cannot improve it ; it is a true measure of my ability to 
make this drawing. 

If these suggestions are faithfully followed throughout this 
course, success awaits any one who earnestly desires it. 

Fig!'i8. To Bisect a Finite Straight Line. — With 
A and -5 in turn as centers, and a radius greater than the half 
of AB, draw arcs intersecting at E and F. Join i5"7^ bisect- 
ing AB at C. 

An arc of a circle may be bisected in the same way. 

fJ^.^io! 'To Erect a Perpendicular at the End of 
THE Line. — Assume the point E above the line as center and 
radius EB describe an arc CBD cutting the line Ar> in the 
point C. From C draw a line through E cutting the arc iii 
D. Draw Di> the joerpendicular. 

Fii^.'^'iio! The Same Problem: a Second Method. — 



i8 



MECHANICAL DRA WING, 



With center B and any radius as BC describe an arc CDE 
with the same radius; measure off the arcs CD dir\d DE. With 
JD and E as centers and any convenient radius describe arcs in- 
tersecting at F. FB is the required perpendicular. 




Prob. 4. 
Fiff. 21. 



Fig. 21. 

To Draw a Perpendicular to a Line 
FROM A Point above or below It. — Assume the point 
C above the Hne. With center C and any suitable radius 
cut the line AB in E and F. From E and F describe arcs 
cutting in D. Draw CD the perpendicular required. 



GEOMETRICAL DRA WING. 



19 



Fi2,^*22; ^^ Bisect a Given Angle. — With A as center 
and any convenient radius describe the arc BC. With B and 
C as centers and any convenient radius draw arcs intersecting 
at D. Join AD, then angle BAD — angle DAC. 




Fig. 22. 

Fi^.^aa.' '^^ Draw a Line Parallel to a Given 
Line AB Through a Given Point C. — From any point 
on AB as B with radius BC describe an arc cutting AB in A, 
From C with the same radius describe arc BD. From B with 
AC 2,^ radius cut arc BD in D. Draw CD. Line CD is paral- 
lel to AB. 

n 




Fh;. 23. 

Fii'.'^'al! From a Point D on the Line DE to set 
OFF an Angle equal to the given Angle BAC — From 



20 



MECHANICAL DRAWING. 



A with any convenient radius describe arc BC. From D with 
the same radius describe arc EF. With center E and radius 
BC cut arc EF in F. Join DF. Angle EDF is = angle BAC. 




Fig. 24. 



Prob. 8. 
Fig. 25. 



To Divide an Angle into t\yo equal 
Parts, when the Lines do not Extend to a Meeting 
Point. — Draw the line CD and CE parallel and at equal dis- 

5 




Fig. 25. 

tances from the lines AB and EG. With C as center and any 
radius draw arcs 1,2. With i and 2 as centers and any con- 



GEOMETRICAL DRAWING. 



21 



venient radius describe arcs intersecting at H. A line through 
C and H divides the angle into two equal parts. 

pfg*^22; To Construct a Rhomboid having Adja- 
cent Sides equal to two Given Lines AB and AC, and 
AN Angle equal to a Given Angle A. — Draw line DE 
equal to AB. Make D = angle A. Make DF ^ AC. From 
/^ with line AB as radius and from E with line AC a.s radius 
describe arcs cutting in G. Join EG and EG. 




I.; 



fK!'* 27*. ^^^ Divide the Like A B into anv Nu:^ir.r-R 
OF EQUAL Parts, sav 15. — Draw a line CD parallel to ABy 
of any convenient length. From C set off along this line the 
number of equal parts into which the hue /^/) is to be di\-ided. 
Draw CA and DB and produce them until they intersect at 
E. Through each one of the points i, 2, 3, 4, etc., draw 
lines to the point E, dividing the line AB into the required 
number of ecjual parts. 

This problem is useful in dividing a hue when the point 
required is difficult to find accurately — e.g., in 1^'ig. 28 .i/? is 
the pitch of the spur gear, partly shown, which inchidcs a 



22 



ME CHA NICAL DRAW.A G. 



space and a tooth and is measured on the pitch circle. In 
cast gears the space is made larger than the thickness of the 
tooth, the proportion being about 6 to 5 — i.e., if we divide 
the pitch into rle\'en equal parts th(^ space ^\ill measure -f^ 




q1 3: 3 4 5 6 7 8-9 1011 1213 lA jy 
Fig, 27. 



Fig 28. 



and the tooth -fj. The j^ which the space is larger than the 
tooth is called the backlash. Let A' B' be the pitch chord of 
the arc AB. Draw CD parallel to A' B' at any convenient 
distance and set off on it i ^ equal spaces of any convenient 
length. Draw CA' and DB' intersecting at E. From point 
5 draw a line to E which will divide A' B' as required; the 
one part y\- and the other j^y. 

Fig.^' 29! To Divide a Given Line into any Number 
OF Equal Parts: Another Method. — Let AB be the 
given line. From A draw AC ^1 any angle, and lay off on it 
the required number of equal spaces of any convenient length. 
Join CB and through the divisions on AC draw lines parallel 
to CB, dividing /4^ as required in the points T, 2', 3', 4^ etc. 

Mg.^' 30! To Divide a Line AB Proportionally to 
THE Divided Line CD — Draw AB parallel to CD at any 



GEOMETRICAL DRA WING. 



23 



distance from it. Draw lines through CA and /)i5 and produce 
them till they meet at E. Draw lines from E through the 
divisions I, 1, 3, 4, etc., of line CD, cutting line AB in the 




dl2S45Q7 89 10 11 1213 I4 b 
Fig. 2q. 

points 5, 6, 7, 8, etc. The divisions on AB will have the 
same proportion to the divisions on CD that the whole line 
AB has to the whole line CD — i.e., the lines will be propor- 
tionally divided. 

E 




proi). 13. jjj^,. Same: Another Method. — Let /^C 
the divided line, make any angle with BA, the line to be di- 



24 



MECHANICAL DRA WING. 



vided at B. Draw line CA joining the two ends of the lines. 
Draw lines from 5, 6, 7, 8, parallel to CA^ dividing line AB 
in points I, 2, 3, 4, proportional to BC 

Fi"^.^' 32*. To Construct an Equilateral Triangle 
ON A Given Base AB. — From the points A and B with AB 
as radius describe arcs cutting in C. Draw lines AC 3.nd BC 
The triangle ABC is equilateral and equiangular. 




Fig. 32 



Fig.^' 33'. 'To Construct an Equilateral Triangle 
OF A Given Altitude, AB. — From both ends oi AB draw 
lines perpendicular to it as CA and DB. From A with any 
radius describe a semicircle on CA and with its radius cut off 
arcs 1,2. Draw lines from A through i, 2, and produce 
them until they cut the base BD. 

Fig^' it'. To Trisect a Right Angle ABC. — From 
the angular point B with any convenient radius describe an 
arc cutting the sides of the angle in C and A. From C and A 
with the same radius cut off arcs i and 2. Draw lines iB and 
2B, and the right angle will be trisected. 



GE OME 7 RICA L DRA WING. 



2; 



l^fi"^' Xk To Construct any Triangle, its Three 
Sides AB and (^7 being given. — From one end of the base 
as A describe an arc with the line B as radius. From the 
other end with Hne C as radius describe an arc, cutting the 
first arc in D. From D draw lines to the ends of line A, and a 
triangle will be constructed having its sides equal to the sides 
given. To construct any triangle the two shorter sides ^ and 
C must together be more than equal to the largest side A. 




Fig. 34. 



l-io. 35- 





Fig. 36. 



Fig. 37. 



Fr^.^* 3«! To Construct a Square, its Base AB 
being given. — Erect a perpendicular at B. Make BC equal 



26 



MECHANICAL DRA WING. 



to AB. From A and C with radius AB describe arcs cutting 
in D. Join DC 2.\\d. DA. 

^\^' 37.* To Construct a Square, given its Di- 
agonal AB. — Bisect AB in C. Draw DF perpendicular to 
AB at C. Make CD and (f/^ each equal to CA. Join ^i>, 
Z>i5, ^i<; and FA. 

Fi"^.^' is! To Construct a Regular Polygon of any 
Number of Side-, the Circumscribing Circle being 
GIVEN. — At any point of contact, as C, draw a tangent AB 
to the given circle. From C with any radius describe a semi- 
circle cutting the given circle. Divide the semicircle into as 
many equal parts as the polygon is required to have sides, as 
I, 2, 3, 4, 5, 6. Draw lines from C through each division, 
cutting the circle in points which will give the angles of the 
polygon. 




Ki.;. ;8. 




Fi^.^* 39! Another Method. — Draw a diameter AB of 
the given circle. Divide AB into as many equal parts as 
the polygon is to have sides, say 5. From A and B with the 



GEOMETRICAL DRAWING. 



27 



line AB as radius describe arcs cutting in C, draw a line from 
C through the second division of the diameter and produce it 
cutting the circle in D. BD will be the side of the required 
polygon. The line C must always be drawn through the 
second division of the diameter, whatever the number of 
sides of the polygon. 

fS^* 40! T*^ Construct any Regular Polygon 
WITH A Given Side AB. — Make BD perpendicular and 
equal to AB. With B as center and radius AB describe arc 
DA. Divide arc DA into as many equal parts as there are 
sides in the required polygon, as i, 2, 3, 4, 5. Draw B2. 
Bisect line AB and erect a perpendicular at the bisection cut- 
ting B2 in C. With C as center and radius CB describe a 
circle. With AB as a chord step off the remaining sides of 
the polygon. 





Fig. 40. 



Fig. 41. 



Prob. 23. Another Method.— Extend line AB. With 

J^If^. '41. 

center A and any convenient radius describe a semicircle. 
Divide the semicircle into as many equal parts as there are 
sides in the required polygon, say 6. Draw lines through 
every division except the first. With A as center and AB as 



28 



MECHANICAL DRAWING. 



radius cut off A 2 in C, From C with the same radius cut A^ 
in I). From D, A4 in £. From B, As in F. ]o'm AC, CD, 
DE, EF, and FB. 

Fi'g.^' fl; To Construct a Regular Heptagon, the 
Circumscribing Circle being given. — Draw a radius AB. 
With B as center and BA as radius, cut the circumference in 
1,2; it will be bisected by the radius in C. C\ or C2 is equal 
to the side of the required heptagon. 




Fig. 42. 




Fi?.^* 43* To Construct a Regular Octagon, the 
Circumscribing Circle being given. — Draw a diameter 
AB. Bisect the arcs AB in C and D. Bisect arcs CA and 
CB in I and 2. Draw lines from i and 2 through the center 
of the circle, cutting the circumference in 3 and 4. Join A\, 
iC, C2, 2B, Bs, etc. 

Fi^.^* IJ To Construct a Pentagon, the Side AB 
being given. — Produce AB. With B as center and BA as 
radius, describe arc AD2. With center A and same radius, 
describe an arc cutting the first arc in D. Bisect AB in E. 



GEOMETRiCAL DRAWING. 



29 



Draw line DE. Bisect arc BD in F. Draw line EF. With 
center C and radius EF cut off arc C\ and i, 2 on the semi- 
circle. Draw line B2 ; it will be a second side of the penta- 




FlG. 44. 

gon. Bisect it and draw a line perpendicular to it at the 
bisection. The perpendiculars from the sides AB and B2 
will cut in G. With G as center and radius GA describe a 
circle* it will contain the pentagon. 




Fig. 45. 



30 



MECHANICAL DRA WING. 



^^' 5 J* To Construct a Heptagon on a Given 
Line AB. — Extend line AB to C. From B with radius AB 
describe a semicircle. With center A and same radius de- 
scribe an arc cutting the semicircle in D. Bisect AB in E. 
Draw line DE. With C as center and DE as radius, cut off 
arc I on the semicircle. Draw line ^i ; it is a second side of 
the heptagon. Bisect it and obtain the center of the circum- 
scribing circle as in the preceding problem. 

Ffg.^' 11*. To Inscribe an Octagon in a Given 
Square. — Draw diagonals AD, CB intersecting at O. From 
A, B, C, and E> with radius equal to AO describe quadrants 
cutting the sides of the square in i, 2, 3, 4, 5, 6, 7, 8. Join 
these points and the octagon will be inscribed. 





Fig. 46. 

^Ig^' 47.' To Construct a Regular Octagon on a 
Given Line AB. — Extend line ^^ in both directions. Erect 
perpendiculars at A and B. With centers A and B and radius 
^^ describe the semicircle CEB and AF2. Bisect the quad- 
rants CE and DE in i and 2, then Ai and B2 will be two 
more sides of the octagon. At i and 2 erect perpendiculars 
J^ 3 and 2, 4 equal to AB. Draw 1-2 and 3-4. Make the 



GEOMETRICAL DRAWING. 



31 



perpendiculars at A and B equal to 1-2 or 3-4 — viz., A^ and 
i56. Complete the octagon by drawing 3-5, 5-6, and 6-4. 

Fri*.^' 4s '^^ Draw a Right Line Equal to Half 
THE Circumference of a Given Circle. — Draw a diam- 
eter AB. Draw line AC perpendicular to AB and equal to 
three times the radius of the circle. Draw another perpen- 
dicular at B to AB. With center B and radius of the circle 
cut off arc BD, bisect it and draw a line from the center of 
the circle through the bisection, cutting line B in E. Join 
EC. Line EC will be equal to half the circumference of 
circle A. 

G 

A C 





l*r.?'^' ?i* To Find a Mean Proportional to two 
Given Right Lines. — Extend the line AB to E making BE 
equal to CD. Bisect AE in F. From /^ with radius FA de- 
scribe a semicircle. At B where the two given lines are 
joined erect a perpendicular to AE cutting the semicircle in 
G. BG will be a mean proportional to CD and AB. 

^I'o"' ?n To Find a Third Proportional (less) to 
TWO Given Right. Lines y^i^ and CD. — Make ^i^= the 
p-ivcn line y^>^. Draw EG =z DC making an an«;lc with EF, 
Join EG. From E with EG as radius cut EP^ h\ II. Draw 



z^ 



MECHANICAL BRA WING. 



H parallel to FG, cutting EG in /. ^/ is the third proper- 
tional (less) to the two given lines. 





d 



c 



D 



Fig. 50. 





G 


L 


/ 


. 


A 




L 


Tfi 


C 




D 




£ 


F 

Fig. 51. 





Fig. 51. -^o riND A Fourth Proportional to three 
Given Right Lines AB, CD, and ^F.— Make GH= the 
given line AB. Draw GI = CD, making any convenient 
angle to GH. Join HI. From G lay off GK = EF. From 
A^ draw a parallel to 77/ cutting GI \n L. GL is the fourth 
proportional required. 





Fig. 52. T.' 

Pig. 53. 

Prob. 34. T-^ TT ^ 

Fig. 52. -^O i^IND THE CENTER OF A GiVEN ArC ABC. 

-Draw the chords ^^ and CD and bisect them. Extend 

the bisection hnes to intersect m D the center required. 



GEOMETRICAL DRAWING. 



33 



FfS.'^* 53*. ^^ Draw a Line Tangent to an Arc of a 
Circle. — (ist.) When the center is not accessible. Let B 
be the point through which the tangent is to be drawn. 
From B lay off equal distances as BE, BF. Join EF and 
through B draw ABC parallel to EF. (2d.) When the cen- 
ter D is given. Draw BD and through B draw ABC perpen- 
dicular to BD. ABC is tangent to the circle at the point B. 

yIS*' sS.' 'To Draw Tangents to the Circle C from 
the Point A without It. — Draw AC and bisect it in E. 
From E with radius EC describe an arc cutting circle C in B 
and D. Join CB, CD. Draw AB and AD tangent to the 
circle C. 





Fig. 54- 



Fig. 55. 



Proh. 37. -^(3 Draw a Tangent between two Cir- 
CLf<S.— -Join the centers A and B. Draw any radial line 
from y4 as A2 and make i-2 — the radius of circle B. From 
A with radius A-2 describe a circle C2D. l^^rom center B 



34 



MECHANICAL DRAWING. 



■draw tangents BC and BD to circle C2D at the points C and 
D by preceding problem. Join AC and AD and through 
the points E and F draw parallels i^6^ and EH to BD and ^6^. 
7^(7 and ^// are the tangents required. 

Fi^.^' ie! ^ o Draw Tangents to two Given Cir- 
cles A and B. — Join A and B. From ^ with a radius 
-equal to the difference of the radii of the given circles de- 





FiG. 56. 



Fig. 57- 



scribe a circle GF. From B draw the tangents BE and BG, 
by Prob. 37. Draw AF and AG extended to E and H. 
Through E and H draw EC and HD parallel to BE and BG 
respectively. EC and Z>// are the tangents required. 

Fig.^' 57! ^^ Draw an Arc of a Circle of Given 
Radius Tangent to two Straight Lines. — AB and AC 
are the two straight lines, and r the given radius. At a dis- 
tance = r draw parallels 1-2 and 3-4 to AC and ^^, inter- 



GEOMETRICAL DRAWING. 



35 



secting at F. From F draw perpendiculars FD and FE. 
With F as center and FD or FE as radius describe the re- 
quired arc, which will be tangent to the two straight lines at 
the points D and E. 

Ffg.^* is! To Draw an Arc of a Circle Tangent 
TO TWO Straight Lines BC and CD when the Mid- 
position G IS given. — Draw CA the bisection of the angle 
BCD and EF at right angles to it through the given point G. 
Next bisect either of the angles FEB or FED. The bisection 
line will intersect the central line CA at A, which will be the 
center of the arc. From A draw perpendiculars A\ and A2, 
and with either as a radius and A as center describe an arc 
which will be tangent to the lines BC and CD at the points i 
and 2. 




Fig. 58 



M^.'^' 59*. To Inscribe a Circle within a Triangle 
ABC. — Bisect the angles A and B. The bisectors will meet 
in D. Draw Di perpendicular to AB. Then with center D 
and radius ^=- D\ describe a circle which will be tangent to 
the given triangle at the points i, 2, 3. 

pTs.^*' «o! To Draw an Arc of a Circle of Given 
Radius A' tangent to two Given Circles A and A'. — 
From A and B draw any radial lines as /i3, B^. Outside 
the circumference of each circle cut off distances 1-3 and 2-4 



36 



MECHANICAL DRA WING. 



each — the given radius R. Then with center A and radius 
^-3, and center B and radius B-/\. describe arcs intersecting at 
C. Draw CA,CB cutting the circles at 5 and 6. With centre 
C and radius (^5 or C6 describe an arc which will be tangent 
at points 5 and 6. 




Fig. 60. 

Fi'g.^* 61! ^^ Draw an Arc of a Circle of Given 
Radius R tangent to two Given Circles A and B 




WHEN THE Arc includes the Circles. — Through A and B 
draw convenient diameters and extend them indefinitely. On 



GEOMETRICAL DRAWING. 



37 



these measure off the distances 1-2 and 3-4, each equal in 
length to the given radius R. Then with center A and radius 
A2, center B and radius ^5*4, describe arcs cutting at C. From 
C draw C^ and C6 through B and A. With center C and ra- 
dius C6 or C^ describe the arc 6, 5, which will be tangent to 
the circles at the points 6 and 5. 

Fi2.^' 62! ^o Draw an Arc of a Circle of Given 
Radius R tangent to Two Given Circles A and B 
WHEN the Arc includes one Circle and excludes the 
OTHER. — Through A draw any diameter and make 1-2 = R, 




From B draw any radius and extend it, making 3-4 = R. With 
center A and radius A2 and center B and radius Ba^ describe 
arcs cutting at C. With C as center and radius = 65 or 6'6 
describe the arc 5, 6. 

^x'^' 03! Draw an Arc of a Circle of Given Ra- 
dius R tangent to a Straight Line AB and a Circle 
CD. — From E^ the center of the given circle, draw an arc of a 



38 



MECHANICAL DRA WING, 



circle i, 2 concentric with CD at a distance R from it, and 
also a straight line 3, 4 parallel to AB at the same distance R 
from AB. DraAv £(9 intersecting CD at 5. Draw the perpen- 
dicular 06. With center O and radius 6^6 or 6^5 describe the 
required arc. 











^ 












A 




^ 


^^-^^^^ \ 


B 




r 


N^ 


^ 




1 


V 


x\ 







^d- 


— ^ 


/ \ . 




4 



,^ 



\. 


/ /\ 




N 




0,^^ 


-t^- 


\ 


1 / ^x' 




ru- 


1 




I 


\ 


/(y^ 


Y«^ 


A 






y 


\^ 


^^^CT 


l-£^ 


^i^N 


v^ 


«^ 


/ 


^ 


6 


► 




6 




B 



Fig. 63. 

Fi"^.^' 64! '^^ Describe an Ellipse Approximately 
BY means of three Radii (F. R. Honey's method). — 




Fig. 64. 

Draw straight lines RH and HQ, making any convenient angle 
at H. With center H and radii equal to the semi-minor and 



GEOMETRICAL DRAWING. 



39 



semi-major axes respectively, describe arcs LM and NO. Join 
LO and draw MK and NP parallel to LO. Lay off Zi —\ 
of LN. Join (9i and draw M2 and ^¥3 parallel to (9i. Take 
7/3 for the longest radius (= T), H2 for the shortest radius 
(= E), and one-half the sum of the semi-axes for the third 
radius (— S), and use these radii to describe the ellipse as 
follows: Let AB and CD be the major and minor axes. Lay 
o& A4 = E send As = S. Then lay oH CG = T and C6 = 5. 
With G as center and G6 as radius draw the arc 6, ^. With 
center 4 and radius 4, 5, draw arc 5, £; intersecting 6, £• at ^.. 
Draw the line G^- and produce it making GS = T. Draw ^, 
4 and extend it to 7 making ^, y = S. With center 6^ and 
radius GC {=T) draw the arc CS. With center^ and radius- 
^, 8 ( = vS) draw the arc 8, 7. With center 4 and radius 4, 7 
{^= E) draw arc 7^. The remaining quadrants can be drawa 
in the same way. 

pT^^' 65* ^^ Draw an Ellipse having given the 
Axes yi^ AND CD. — Draw AB and CD at right angles to and 
bisecting each other at E. With center 6^ and radius EA cut 
AB in E and E' the foci. Divide EE or EE' into a number of 
parts as shown at i, 2, 3, 4, etc. Then with /^ and E' as cen- 

6* 




Fig. 65. 



Fig. 66. 



Fig. 67. 



ters and A\ and Bi, and Az and ^2, etc., as radii describe arcs 
intersecting in R, S, etc., until a sufficient number of points 



40 



MECHANICAL DRA WING. 



are found to draw the elliptic curve accurately throughout. 
(No. 5 of the ''Sibley College Set" of irregular curves is 
very useful in drawing this curve.) To draw a tangent to 
the ellipse at the point G \ Extend FG and draw the bisector 
of the angle HGF' . KG is the tangent required. 

Fig.^'el: Another Method.— Let ^^ and AC be the 
semi axes. With A as center and radii AB and AC describe 
circles. Draw any radii as y43 and ^4, etc. Make 3 i, 42, 
etc., perpendicular to AB, and D2, E^, etc., parallel to AB. 
Then i, 2, 5, etc., are points on the curve. 

Fig.^* 6?'. Another Method. — Place the diameters as 
before, and construct the rectangle CDEF. Divide AB and 
DB and BF into the same number of equal parts as i, 2, 3 and 
B. Draw from C through points I, 2, 3 on AB and BD 
lines to meet others drawn from E through points i, 2, 3 on 
A.B and FB intersecting in points GHK. GHK are points on 
the curve. 

Fig.^* 68.' Another Method. — Place the diameters AB 
and CD as shown in Drawing No. i. Draw any conveniejit 

'1 




Fig. 68. 



angle RHQ, Drawing No. 2. With center ^ and radii equal 
to the semi-minor and semi-major axes describe arcs ZJ/ and 



GEOMETRICAL DRAWING. 4 1 

NO. Join LO and draw MK and NP parallel to LO. Then 
from 6^ and D with a distance = ///^ lay off the points i i' on 
the minor axis and from A and B with a distance = //A" lay 
ofT the points 2 2' on the major axis. With centers 1,1', 2 and 
2' and radii \—D and 2-i?, respectively, draw arcs of circles. 
On a piece of transparent celluloid Zlay off from the point G, 
GF and GE = the semi-minor and semi-major axes respec- 
tively. Place the point i^on the major axis and the point £ on 
the minor axis. If the strip of celluloid is now moved over 
the figure, so that the point £ is always in contact with the 
semi-minor axis and the point F with the semi major axis, the 
necessary number of points may be marked through a small 
hole in the celluloid at G with a sharp conical-pointed pencil, 
and thus complete the curve of the ellipse between the arcs of 
circles. 

Fw^' 69! '^^ Construct a Parabola, the Base CD 
AND THE Abscissa AB being given. — Draw FF through A 
parallel to CF and CF and DF parallel to AB. Divide AF, 
AF, FC, and FD into the same number of equal parts. 
Through the points i, 2, 3 on AF and AF draw lines parallel 
to AB, and through A draw lines to the points 1,2, 3 on FD 
and FC intersecting the parallel lines in points 4, 5, 6, etc., of 
the curve. 

Prob. 52. Given the Directrix BD and the Focus C 
TO Draw a Parabola and a Tangent to Pr at the Point 
3. — The parabola is a curve such that every point in the curve 
is equally distant from the directrix ^Z^ and the focus C. The 
vertix F is equally distant from the directrix and the focus, 
i.e. CF is = FB. Any line parallel to the axis is a diameter. 
A straight line drawn across the figure at right angles to the 



42 



MECHAXICAL DRA IVIXG. 



axis is a double ordinate, and either half of it is an ordinate. 
The distance from C to any point upon the curve, as 2 is 
always equal to the horizontal distance from that point to the 
directrix. Thus Ci — i. i' , C2 to 2, 2', etc. Through C 
draw ACF at right angles to BD, ACF is the axis of the 



Ai ^ 3 F 






^ 


^ 


yj) 


















^ 


^ 


^ 


k? 


D 










N 


\\\ 


^ 


^ 














"^ 


P 


m 


\ 


vi 


A 












d 


/ 


B 

i 


F 




/' 










^> 


^ 


^2 
3 


4 








-> 


<^ 


1, 

T 






\ 


-> 


< 


5 















Fig. 70. 

curve. Draw parallels to BD through any points in AB, and 
with center C and radii equal to the horizontal distances of 
these parallels from BD describe arcs cutting in the points I, 
2, 3, 4, etc. These are points in the curve. The tangent to 
the curve at the point 3 may be drawn as follows : Produce 
AB to F. Make EF ^ the horizontal distance of ordinate 33 
from E. Draw the tangent through 3^^"^. 

Prob. 53. -pQ Draw ax Hyperbola, having given 
THE Diameter AB, the Abscissa BD, and Double Ordi- 
nate EF. — ]\Iake F4. parallel and equal to BD. Divide DF 
and F4. into the same number of equal parts. From B draw 
lines to the points in 4.F and from A draw lines to the points 
in DF. Draw the curve through the points where the lines 
correspondingly numbered intersect each other. 



GE ME TRIG A L DRA WING 



45 



pfg.''' 72.* To Construct an Oval the Width AB 
BEING GIVEN.— Bisect AB by the line CD in the point E, 
and with ^ as center and radius ^^ draw a circle cutting CD in 





Fig. 71. 



Fig. 72. 



F. From A and ^draw lines through F. From A and B with 
radius equal to AB draw arcs cutting the last two lines in G 
and H. From F with radius FG describe the arc GH to meet 
the arcs AG and BH, which will complete the oval. 

pfg.^' 73! Given an Ellipse to Find the Axes and 
Foci. — Draw two parallel chords AB and CD, Bisect each 
of these in E and F. Draw t^"/^ touching the ellipse in i and 
2. This line divides the ellipse obliquely into equal parts. 
Bisect I, 2 in G, which will be the center of the ellipse. From 
G with any radius draw a circle cutting the ellipse in H IJK. 
Join these four points and a rectangle will be formed in the 
ellipse. Lines LM and NO, bisecting the sides of the 
rectangle, will be the diameters or axes of the ellipse. With 
iV or (9 as centers and radius = GL the semi-major axis, de- 
scribe arcs cutting the major axis in P and Q the foci. 

Proi). .JO. jQ Construct a Spiral ok one Revolu- 

Fij;. 74. 

TION. — Describe a circle using the widest limit of the s[)iral as 



44 



MECHAXICAL DRA WING. 



a radius. Divide the circle into any number of equal parts as 
A, B, C, etc. Divide the radius into the same number of equal 
parts as i to 12. From the center with radius 12, i describe 
an arc cutting the radial line B in i'. From the center con- 
tinue to draw arcs from points 2, 3, 4, etc., cutting the corre- 
sponding radii C, D, E, etc. in the points 2', 3', 4', etc. From 
12 trace the Archimedes Spiral of one revolution. 



K A 





\ 



Fig. 73. 

?i'^^' %k To Describe a Spiral of any Number of 
Revolutions, e.g., 2. — Divide the circle into any num- 
ber of equal parts as ^, B, C, etc., and draw radii. Divide 
the radius ^12 into a number of equal parts corresponding 
with the required number of revolutions and divide these 
into the same number of equal parts as there are radii, viz., 
I to 12. It will be evident that the figure consists of two 
separate spirals, one from the center of the circle to 12, and 
one from 12 to y^. Commence as in the last problem, draw- 
ing arcs from i, 2, 3, etc., to the correspondingly numbered 
radii, thus obtaining the points marked i', 2', 3', etc. The 
first revolution completed, proceed in the same manner to 
find the points \'\ 2", ^" , etc. Through these points trace 
the spiral of two revolutions. 



GEOMETRICAL DRAWING. 



45 



^f.?^* 52* To Construct the Involute of the Cn<- 
CLE O. — Divide the circle into any number of equal parts 
and draw radii. Draw tangents at right angles to these radii. 
On the tangent to radius i lay off a distance equal to one 
of the parts into which the circle is divided, and on each of 

A 

— -^ T 

A 





the tangents set off the number of parts corresponding to the 
number of the radii. Tangent 12 will then be the circumfer- 
ence of the circle unrolled, and the curve drawn through the 
extremities of the other tangents will be the involute. 

Ff-.^* 77'. '^^ Descru^e an Ionic Volute. — Divide the 
given height into seven equal parts, and through the point 3 
the upper extremity of the third division draw 3, 3 perpen- 
dicular to AB. From any convenient point on 33 as a cen- 
ter, with radius equal to one-half of one of the divisions on 
AB, describe the eye of the volute NPNM, shown enlargctl 
at Drawing No. 2. iVTV corresponds to line 3, 3, Drawing 
No. I. Make PM perpendicular to AW and inscribe the 
square TV/W^'l/, bisect its sides and draw the square 11, 12, 



46 



MECHANICAL DRAWING. 



13, 14. Draw the diagonals ii, 13 and 12, 14 and divide 
them as shown in Drawing No. 2. At the intersections of 
the horizontal with the perpendicular full lines locate the 
points I, 2, 3, 4, etc., which will be the centers of the quad- 
rants of the outer curve. The centers for the inner curve 
will be found at the intersections of the horizontal and per- 



.-; 


C 






■\ 




7 








..6 






^X 




.5 


JVoJ. ^ 


r 


\ 


\ 


-* / 


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\\^ 


\ 


' / 


( M 




\\ ' 


\r, 


^vuy, 1 i/v 1 \ . 


- 1 


j JJ-.'Vfc 




w 


// i 


1 " 


^r 


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-' \ 


y V 




^ / 


/ 






/ 




yy 


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E 








Fig. 77. 
pendicular broken lines, drawn through the divisions on the 
diagonals. Then with center i and radius iP draw arc PA^, 
and with center 2 and radius 2iV draw arc A^M, with center 3 
and radius 3 J/ draw arc ML, etc. The inner curve is drawn 
in a similar way, by using the points on the diagonals indi- 
cated by the broken lines as centers.- 

m2.^' Ts! To Describe the Cycloid. — AB is the di- 
rector, CB the generating circle, X a piece of thin transparent 
celluloid, with one side dull on which to draw the circle C. 
At any point on the circle C puncture a small hole with a 
sharp needle, and place the point C tangent to the director 
AB at the point from which the curve is to be drawn. Hold 
the celluloid at this point with a needle, and rotate it until 



GEOMETRICAL DRAWING. 



47 



the arc of the circle C intersects the director AB. Through 
the point of intersection stick another needle and rotate X 
until the circle is again tangent to AB, and through the punc- 
ture at C with a 4H pencil, sharpened to a fine conical point, 
mark the first point on the curve. So proceed until sufficient 
points have been found to complete the curve. 

(Note. — The thin celluloid was first used as a drawing 
instrument by Professor H. D. Williams, of Sibley College, 
Cornell University.) 

Ffg.^' 79'. To Find the Length of a Given Arc of a 
Circle approximately. — Let BC be the given arc. Draw 
its chord and produce it to A, making BA equal half the 





-r- 


c 


^/ 1 

Si / 

21 / 


V 




A 




B 




Fig. 78. 



Fig. 79. 



chord. With center ^4 and radius ^6^ describe arc (7/^ cut- 
ting the tangent line BD at D, and making it equal to the 
arc BC. 

^r^^'- ^g; To Describe the Cycloid by the Old 
Method — Divide the director and the generating circle into 
the same number of equal parts. Through the center a draw 
ag parallel to AB for the line of centers, and divide it as AB 
in the points^, c, d, e, f, and g. With centers/, c, d, etc., de- 
scribe arcs tangent to AB, and through the points of division 
on the generating circle 1,2, 3, etc., draw lines parallel to 



4S 



MECHANICAL BRA WING. 



AB cutting the arcs in the points i', 2' , 3', etc. These will be 
points in the curve. 

An approximate curve may be drawn by arcs of circles. 
Thus, taking/' as center and f'g' as radius, draw arc g'l'. 




I 



Fig. 80. 



Produce I'f and 2'e' until they meet at the center of the 
second arc 2'f', etc. 

m^^' 81! To Describe the Epicycloid and the 
Hypocycloid. — Divide the generating circle into any num- 
ber of equal parts, i, 2, 3, etc., and set off these lengths from 
C on the directing circle CB as e\ d\ c\ etc. From A the cen- 
ter of the directing circle draw lines through e\ d' , c , etc., cut- 
ting the circles of centers in ^, d, c, etc. From each of these 
points as centers describe arcs tangent to the directing circle. 
From center A draw arcs through the points of division on 
the generating circle, cutting the arcs of the generating circles 
in their several positions at the points i\ 2', 3', etc. These 
will be points in the curve. 

Mg.^* Hi Another Method. — Draw the generating 
circle on the celluloid and roll it on the outside of the gener- 
ating circle BC for the Epicycloid, and on the inside for the 



GEOMETRICAL DRAWING. 



49 



Hypocycloid, marking the points in the curve 1,2, 3, etc., in 
similar manner to that described for the Cycloid. 



Fig. 82. 




Fig. 81. 



Fig. 83. 



^\2^' %%\ To Draw the Cissoid. — Draw any line AR 
and BC perpendicular to it. On BC describe a circle. From 
the extremity C of the diameter draw any number of lines, 
at any distance apart, passing through the circle and meeting 
the line AB in i' , 2', 3', etc. Take the length from ^ to 9 
and set it off from C on the same line to g'\ Take the dis- 
tance from 8' to 8 and set it off from C on the same line to 
8", etc., for the other divisions, and through 9", 8'', 7", 6",. 
etc., draw the curve. 



50 



MECHANICAL DRAWING. 



Fig.^' Ia! To Draw Schiele's Anti-friction Curve. 
— Let AB be the radius of the shaft and ^i, 2, 3, 4, etc., its 
axis. Set off the radius AB on the straight edge of a piece 
of stiff paper or thin celluloid and placing the point B on the 
■division i of the axis, draw through point ^4 the line A\, 
Then lower the straight edge until the point B coincides with 
2 and the point A just touches the last line drawn, and draw 
^2, and so proceed to find the points a, b, c, etc. Through 
these points draw the curve. 





Fig. 84. 



Fig. 85. 



Fi*g.^' is! ^^ Describe an Interior Epicycloid. — 
Let the large circle X be the generator and the small circle 
Y the director. Divide circle Y into any number of equal 
parts, as B, H, /, /, etc. Draw radial lines and make HC, 
ID^ JE, KF, etc., each equal to the radius of the generator 
X. With centers C, D, E, etc., describe arcs tangent at 
//", /,y, etc. Make Hi equal to one of the divisions of the di- 
rector as BH. Make I2 equal to two divisions, ^3, three divi- 
sions, etc., and draw the curve through the points i, 2, 3, 4, 



GEOMETRICAL DRAWING. 



51 



etc. This curve may also be described with a piece of cellu- 
loid in a similar way to that explained for the cycloid. 

It may not be out of place here to describe a few of the 



MOULDINGS USED IN ARCHITECTURAL WORK, 

since they are often found applied to mechanical constructions. 
Fi2.^' se! T^ Describe the "Scotia." — i, i is the top 
line and 4, 4 the bottom line. From i drop a perpendicular 
I, 4; divide this into three equal parts, as i, 2, and 3. 
Through the point 2 draw ab parallel to I, i. With center 2 
and radius 2, i describe the semicircle a\b, and with center b 
and radius ba describe the arc ^5 tangent to 4, 4 at 5, draw 
the fillets i, i and 4, 4. 



I 


1 


A 


A 


\ 


3 


L U » 




Fig. 86. 



Fig. 87. 



Fi'g.^'87! To Describe the " Cyma Recta."— Join i, 
3 and divide it into five equal parts, bisect i, 2 and 2, 3, and 
with radius equal to 1 , 2 and 2, 3 respectively describe arcs 
I, 2 and 2,3. Draw the fillets i, i and 3, 3 and complete the 
moulding. 

Ffg.^'ss! To Describe the "Cavetto" or "Hol- 
low." — Divide the perpendicular i, 2 into three equal parts 
and make 2, 3 equal to two of these. P>om centers i and 3 
with a radius somewhat greater than the half of 1,3, describe 
arcs intersecting at the center of the arc 1,3, 



52 



ME CHA NIC A L DRA WING. 



Fi<^^' 89* '^^ Describe the "Echinus,'* ''Quarter 
Round," or ''Ovolo." — Draw i, 2 perpendicular to 2, 3, 
and divide it into three equal parts. Make 2, 3 equal to 
two of these parts. From the points 2 and 3 with a radius 
greater than half 1,3, describe arcs cutting in the center of 
the required curve. 




Prob. 72. jQ Describe the "Apophygee." — Divide 

Fig. 90. 

3, 4 into four equal parts and lay off five of these parts from 
3 to 2. From points 2 and 4 as centers and radius equal to 
2,3, describe arcs intersecting in the center of the curve. 





Fig. 90. 



Fig. 91. 



pfg.^* 9?: To Describe the '' Cyma Reversa."— Make 
4, 3 z= 4, I. Join I, 3 and bisect it in the point 2. From the 
points I, 2 and 3 as centers and radii equal to about two-thirds 
of I, 2 draw arcs intersecting at 5 and 6. Points 5 and. 6 
are the centers of the reverse curves. 

fS.^" 92! To Describe the '' Torus." — Let i, 2 be the 
breadth. Drop the perpendicular i, 2, and bisect it in the 



GEOMETRICAL DKAWIKG. 



53 



point 3. With 3 as center and radius 3, I, describe the semi- 
circle. Draw the fillets. 





Fig. 92. 



Fig. 93. 



Mg!' 93! ^'^ Arched Window Opening. — The curves 
are all arcs of circles, drawn from the three points of the equi- 
lateral triangle, as shown in the figure. 

fS.^'oi: To Describe the '' Trefoil."— The equi- 
lateral triangle is drawn first, and the angle 1,2,3 bisected by 
the line 2, 4, which also cuts the perpendicular line I, 6 in the 
point 6. The center of the surrounding circles i, 2 and 3 are 
the centers of the trefoil curves. 

yh?^" 95. T^^ Descrh^e the " Quatre Foil." — Draw 
the square i, 2, 3, 4 in the position shown in the figure. The 
center of the surrounding circles, point 5, is at the intersection 
of the diagonals of the square. Points I, 2, 3, 4 of the square 
are the centers of the small arcs. 

S^'"^' o?* To Describe the " Cinquefoil Orna- 

h\^. 9u. *- 

MENT." The curves of the cinquefoil are described from the 

corners of a pentagon i, 2, 3, 4, 5. Bisect 4, 5 in 6 and draw 
2, 6, cutting the perpendicular in the point 7, the center of 
the large circles. 

Fr.^*" 97! To Draw a Baluster. — Begin b\- drawing 
the center line, and lay off the extreme perpendicular hciglit, 



54 



MECHAXICAL DRA WING. 



the intermediate, perpendicular, and horizontal dimensions, 
and finally the cur\-es as shown in the figure. 



Fig. 94. 



Fig. 95. 



Fig. 96. 




riG. 97. 



DRAAVIXG TO SCALE. 

AMien we speak of a drawing as having been made to scale, 
we mean that every part of it has been drawn proportionately 
and accurately. €\\.\\^x full size, reduced o^c enlarged. 

Very small and complicated details of machinery are usu- 
ally drawn enlarged ; larger details and small machines may 
be made full size, v.diile larger machines and large details are 
shown reduced. 

When a drawing of a machine is made to a reduced or en- 
larged scale the figures placed upon it should always give the 
full-size dimensions, i.e., the sizes the machine should meas- 
ure when finished. 



GEOMETRICAL DRAWING. 



55 



\\^' 9s" To Construct a Scale of Third Size or 
/^' — I Foot. — Draw upon a piece of tough white drawing- 
paper two parallel lines about i" apart and about 14" long as 
shown by a^ Fig. 98. From A lay off distances equal to a^' 
and divide the first space AB into 12 equal parts or inches by 
Prob. 12. Divide AE in the same way into as many parts as 

it may be desired to subdivide the inch divisions on AB, 
E 







^ V 








I 


"A" 


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A 


A / 


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a 








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\ 


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\ 








\ 


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1 


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L_ 


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V 


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V 


V. 


K 


\ 


rv 1 




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\ 


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V 


\ 


V 


L 


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i i 


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M I 


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1, 2.Jlctual inches =lf 

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19. 


9- a- 


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11' w 1 


8- 7' 


,r 4" 1 


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Scale /=^lfoot. 


h 


















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1 
















1 


















































1 






II 


II 


II 


II 


nil! 


III 


, 


III 


II 


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[il 


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Fig. 98. 

usually 8. When the divisions and subdivisions have been 
carefully and lightly drawn in pencil, as shown by a, in Fig. 
98, then the lines denoting \" ,^' , \" , i", and 3" should be 
carefully inked and numbered as shown by {b). By a further 
subdivision a scale of 2" ^^ i foot may easily be made as shown 
by {c) in Fig. 98. 



CHAPTER III. 
CONVENTIONS. 

It is often unnecessary if not undesirable to represent cer- 
tain things as they would actually appear in a drawing, espe- 
cially when much time and labor is required to make them 
orthographically true. 

So for economic reasons draftsmen have agreed upon con- 
ventional methods to represent many things that would other- 
Avise entail much extra labor and expense, and serve no par- 
ticular purpose. 

It is very necessary, however, that all draftsmen should 
know Jioiv to draw these things correctly, for occasions will 
often arise when such knowledge will be demanded ; and be- 
sides it gives one a feeling of greater satisfaction when using 
conventional methods to know that he could make them artis- 
tically true if it was deemed necessary. 

STANDARD CONVENTIONAL SECTION LINES. 

Conventional section lines are placed on drawings to distin- 
guish the different kinds of materials used when such drawings 
are to be finished in pencil, or traced for blue printing, or to 
be used for a reproduction of any kind. 

Water-colors are nearly always used for finished drawings 

and sometimes for tracings and pencil drawings. 

The color tints can be applied in much less time than it 

56 



CON VEN TIONS. 5 7 

takes to hatch-line a drawing. So that the color method 
should be used whenever possible. 

Fig. 99. — This figure shows a collection of hatch-lined 
sections that is now the almost universal practice among 
draftsmen in this and other countries, and may be considered 
standard. 

No. I. To the right is shown a section of a wall made of 
rocks. When used without color, as in tracing for printing, 
the rocks are simply shaded with India ink and a 175 Gillott 
steel pen. For a colored drawing the ground work is made 
of gamboge or burnt umber. To the left is the conventional 
representation of water for tracings. For colored drawings 
a blended wash of Prussian blue is added. 

No. 2. Convention for Marble. — When colored, the 
whole section is made thoroughly wet and each stone is then 
streaked with Payne's gray. 

No. 3. Convention for Chestnut. — When colored, a 
ground wash of gamboge with a little crimson lake and burnt 
umber is used. The colors for graining should be mixed in a 
separate dish, burnt umber with a little Payne's gray and 
crimson lake added in equal quantities and made dark enough 
to form a sufficient contrast to the ground color. 

No. 4. General Convention for Wood. — When colored the 
ground work should be made with a light wash of burnt sienna. 
The graining should be done with a writing-pen and a dark 
Aiixture of burnt sienna and a modicum of India ink. 

No. 5. Convention for Black Wabiut. — A mixture of 
Payne's gray, burnt umber and crimson lake in equal quanti- 
ties is used for the ground color. The same mixture is used 
for graining when made dark by adding more burnt umber. 



58 



MECHANICAL DRAWING. 




CONVEX TIOXS. 59 

No. 6. Convention for Hard Pine. — For the ground 
color make a light wash of crimson lake, burnt umber, and 
gamboge, equal parts. For graining use a darker mixture of 
of crimson lake and burnt umber. 

No. 7. Convention for Building-stone. — The ground 
color is a light wash of Payne's gray and the shade lines are 
added mechanically with the drawing-pen or free-hand with 
the writing-pen. 

No. 8. Convention for Eartli. — Ground color, India ink 
and neutral tint. The irregular lines to be added with a writ- 
ing-pen and India ink. 

No. 9. Seetion Lining for Wrought or Malleable Iron. — 
When the drawing is to be tinted, the color used is Prussian 
blue. 

No. 10. Cast Iron. — These section lines should be drawn 
equidistant, not very far apart and narrovv'er than the body 
lines of the drawing. The tint is Payne's gray. 

No. 1 1. Steel. — This section is used for all kinds of steel. 
The lines should be of the same width as those used for cast- 
iron and the spaces between the double and single lines should 
be uniform. The color tint is Prussian blue with enough crim- 
son lake added to make a warm purple. 

No. 12. Brass. — This section is generally used for all 
kinds of composition brass, such as gun-metal, yellow metal, 
bronze metal, Muntz metal, etc. The width of the full lines. 
dash lines and spaces should all be uniform. The color tint. 
is a light wash of gamboge. 

Nos. 13-20. — The section lines and color tints for those 
numbers are so plainly given in the figure that further instruc- 
tion would seem to be superfluous. 



Co MECHANICAL DRAWING. 

CONVENTIONAL LINES. 

Fig. ioo. — There are four kinds: 

(i) TJic Hidden Line. — This Hne should be made of short 
clashes of uniform length and width, both depending some- 
what on the size of the drawing. The width should always 

■be slightly less than the body lines of the drawing, and the 

^i) 



4 



((2) — 

;(3)- 
(4) — 



Fig. ioo, 

length of the dash should never exceed \" . The spaces 
between the dashes should all be uniform, quite small, never 
exceeding -x-^" - This line is always inked in with black ink. 

(2) TJie Line of Motion. — This line is used to indicate 
point paths. The dashes should be made shorter than those of 
the hidden line, just a trifle longer than dots. The spaces 
should of course be short and uniform. 

(3) Center Lines. — Most drawings of machines and parts 
of machines are symmetrical about their center lines. When 
penciling a drawing these lines may be drawn continuous and 
as fine as possible, but on drawings for reproductions the black- 
inked line should be a long narrow dash and two short ones 
alternately. When colored inks are used the center line should 
be made a continuous red line and as fine as it is possible to 
make it. 

(4) Dimension Lines and Line of Section. — These lines 
are made in black with a fine long dash and one short dash 
alternately. In color they should be continuous blue lines. 



CONVENTIONS. 



6i 



Colored lines should be used wherever feasible, because they 
are so quickly drawn and when made fine they give the drawing- 
a much neater appearance than when the conventional black 
lines are used. Colored lines should never be broken. 



CONVENTIONAL BREAKS. 

Fig. ioi. — Breaks are used in drawings sometimes to indi- 
cate that the thing is actually longer than it is drawn, some- 



33 



3ca 



^.^^^^^^^^^^^^^^^^^^.^'.^■^^^^^^^^^^^^ 



v^^^^^^^^>v.^.^,^^^^^^^^^^^^^^^^^^^^^^^^^ 



"=l 



Fig. ioi. 



times to show the shape of the cross-section and the kind of 
material. Those given in Fig. lOi show the usual practice. 



CROSS-SECTIONS. 

Fig. 102. — When a cross-section of a pulley, gear-wheel 
or other similar object is required and the cutting-plane passes 
through one of the spokes or arms, then only the rim and hub 
should be sectioned, as shown at xx No. i and zz No. 2, and 
the arm or spoke simply outlined. Cross-sections of the arms 
may be made as shown at A A No. 2. In working drawings of 



62 



MECHANICAL DRAWING. 



gear-wheels only the number of teeth included in one quadrant 
need be drawn ; the balance is usually shown by conventional 
lines, e.g., i\iQ pitch line the same as a center line, viz., a long 

z 




Fig. 102. 

dash and two very short ones alternately or a fine continuous 
red line. 

The addenduvi line {d) and the root or bottom line {b) the 
same as a dimension line, viz., one long dash and one short 
dash alternately or a fine continuous blue line. The end ele- 
vation of the gear-teeth should be made by projecting only 
the points of the teeth, as shown at No. 2. 



CONVENTIONAL METHODS OF SHOWING SCREW-THREADS IN 

WORKING DRAWINGS. 

Fig. 103. — No. i, shows the convention for a double 
V thread, U. S. standard; No. 2, a single V thread; No. 3, 
a single square thread; No. 4, a single left-hand V thread; 
No. 5, a double right hand square thread; No. 6, any 
thread of small diameter; No. 7, any thread of very small 
diameter. The true methods for constructing these threads 
are explained on pages 99-101, Figs. 137— 139. 

In No. 6. the short wide line is equal to the diameter 
of the thread at the bottom. The distance between the 



CONVENTIONS. 



63 



longer narrow lines is equal to the pitch, and the Inclination 
is equal to half the pitch. 

The short dash lines in No. 7 should be made to corre- 





L^ bfJ 



Fig. 103. 



spond to the diameter of the thread at the bottom. After 
some practice these lines can be drawn accurately enough by 
the eye. 



1 



CHAPTER IV. 
LETTERING AND FIGURING. 

This subject has not been given the importance it deserves 
in connection with mechanical drawing. Many otherwise ex- 
cellent drawings and designs as far as their general appearance 
is concerned have been spoiled by poor lettering and figuring. 

All lettering on mechanical drawings should be plain and 
legible, but the letters in a title or the figures on a drawing 
should never be so large as to make them appear more prom- 
inent than the drawing itself. 

The best form of letter for practical use is that which gives 
the neatest appearance with a maximum of legibility and re- 
quires the least amount of time and labor in its construction. 

This would naturally suggest a " free-hand " letter, but be- 
fore a letter can be constructed '' free-hand " with any degree 
of efficiency, it will be necessary to spend considerable time 
in acquiring acknowledge of the form and proportions of the 
particular letter selected. 

It is very desirable then that after the student has care- 
fully constructed as many of the following plates of letters and 
numbers as time will permit and has acquired a sufficient 
knowledge of the form and proportions of at least the " Ro- 
man " and " Gothic" letters; he should then adopt some one 

64 



LETTERING AND FIGURING. 6$ 

style and practice that at every opportunity, until he has at- 
tained some proficiency in its free-hand construction. 

When practicing the naaking of letters and numbers Tree- 
hand, they should be made quite large at first so as to traia 
the hand. 

The " Roman " is the most legible letter and has the best 
appearance, but is also the most difficult to make well, either 
free-hand or mechanically. However, the methods given for 
its mechanical construction. Figs. 104 and 105, will materially 
modify the objections to its adoption for lettering mechanical 
drawings. 

The *' Gothic" letter is a favorite with mechanical drafts- 
men, because it is plain and neat and comparatively easy to 
construct. (See Fig. 106.) 

Among the type specimens given in the following pages 
the Bold-face Roman Italic on page 70 is one of the best 
for a good, plain, clear, free-hand letter, and is often used 
with good success on working drawings. Gillott's No. 303 
steel pen is the best to use when making this letter free-hand. 

The " Yonkers " is a style of letter that is sometimes 
used for mechanical drawings. It is easy to construct with 
either F. Soennecken's Round Writing-pens, single point, or 
the Automatic Shading pen. But it lacks legibility, and is 
therefore not a universal favorite. 

A good style for *' Notes" on a drawing is the " Gothic 
Condensed " shown on page 70. 

When making notes on a drawing with this letter, the 
only guides necessary are two parallel lines, drawn light 1\' in 
pencil. The letters should be sketched lightly in pencil firsts 



66 MECHANICAL DRA WIXG. 

and then carefully inked, improving spacing and proportions 
to satisfy the practiced eye. 

FIGURING. 

Great care should be taken in figuring or dimensioning a 
mechanical drawing, and especially a working drawing. 

To have a drawing accurately, legibly, and neatly figured 
is considered by practical men to be the most important part 
of a working drawing. 

There should be absolutely no doubt whatever about the 
character of a number representing a dimension on a drawing. 

Many mistakes have been made, incurring loss in time, 
labor, and money through a wrong reading of a dimension. 

Drawings should be so fully dimicnsioned that there will 
be no need for the pattern-maker or machinist to measure any 
part of them. Indeed, means are taken to prevent him from 
doing so, because of the liability of the workman to make 
mistakes, so drawings are often made to scales which are dif- 
ficult to measure with a common rule, such as 2'' and /^' = 
I ft. 

The following books, among the best of their kind, are 
recommended to all who desire to pursue further the study 
of " Lettering" : F/at7i Lettering, by Prof. Henry S. Jacoby, 
Cornell University, Ithaca, N. Y. ; Lettering, by Charles W. 
Reinhardt, Chief Draftsman, Engineering Nezvs, New York ; 
Free-Jiand Lettering, by F. T. Daniels, instructor in C. E. in 
Tufts College. 



LETTERING AND FIGURING. 



67 




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MECHANICAL DRA WING. 





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LETTERIXG AND FIGURING. 



69 




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70 MECHAXICAL DRAWIXG. 

iS-Point Roman. 

ABCDErGHlJKLM:XOPQRSTUYWX 
YZ abcclefgliij klmnopqrstuvwxTz 

1234567890 

iS-Point Italic. 

AB CDEFGHIJKLJIXOP QESTUV 

WXYZ ahcdefgh [jMmnopqrstuvifxyz 

i.-'.-Point Gushing Italic. 

ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklm 
nopqrstuvwxyz 1234567890 

2S-Point Boldface Italic. 

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XOPQRSTUVWXYZ 

ahcdefghijhhnnopqrstu 

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Two-Line Nonpareil Gothic Condensed. 

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LETTERING AND FIGURING. 7 1 

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72 MECHAMCAL DRA WING. 

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LETTERING AND FIGURING. 73 

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CHAPTER V. 
ORTHOGRAPHIC PROJECTION. 

Orthographic Projection, sometimes called Descrip- 
tive Geometry and sometimes simply Projection, is one of 
the divisions of descriptive geometry; the other divisions are 
Spherical Projection, Isometric Projection, Shades and 
Shadows, and Linear Perspective. 

In this course we will take up only a sufficient number of 
the essential principles of Orthographic Projection, Isometric 
Projection, and Shades and Shade Lines, to enable the stu- 
dent to make a correct mechanical drawing of a machine or 
other object. 

Orthographic Projection is the science and the art of rep- 
resenting objects on different planes at right angles to each 
other, by projecting lines from Xh^ point of sight through the 
principal points of the object perpendicular to the Planes of 
Projection. 

There are commonly three planes of projection used, viz., 
the H. P. or Horizontal Plane, the V. P. ox Vertical Plane y 
and the Pf. P, or Profile Plane. 

These planes, as will be seen by Figs. 107 and 109, inter- 
sect each other in a line called the /. L. or Intersecting Line, 
and form four angles, known as the first, second, third, and 

74 



GR 1 HOGRA PHIC PR OJE C 7 ION. 



75 



fourth Dihedral Angles. Figs. 107 and 109 are perspective 
views of these angles. 

An object may be situated in any one of the dihedral 
angles, and its projections drawn on the corresponding co- 
ordinate planes. 

Problems in Descriptive Geometry are usually worked out 
in the first angle, and nearly all English draftsmen project 
their drawings in that angle, but in the United States the 
third angle is used almost exclusively. There is good reason 
for doing so, as will be shown hereafter. 

We will consider first a few projection problems in the 
first angle, after which the third angle will be used throughout. 




Fig. 107. 

H.P., Fig. 107, is the Horizontal Plane, V.P. the Vertical 
Plane, and I.L. the Intersecting Line. 

The Horizontal Projection of a point is where a perpen- 
dicular line drawn through the point pierces the H.P. 

The Vertical Projection of a point is where a per. line 
drawn through the point pierces the V.P. 

Conceive the point a, Fig. 107, to be situated in space 4" 
above the H.P. and 3" in front of the V.l\ If a line is 
passed through the point n per. to II. P. and produced until 



^6 MECHANICAL DRAWING. 

it pierces the H.P. in the point a}\ a" will be the Hor. Proj, 
of the point a. 

If another line is projected through the point <3: per. to the 
V.P. until it pierces the V.P. in the point a^, a" is the ver- 
tical projection of the point a. 

If now the V.P. is revolved upon its axis I.L. in the di- 
rection of the arrow until it coincides with the H.P. and let 
the H.P. be conceived to coincide with the plane of the 
drawing-paper, the projections of the point a will appear as 
shown by Fig. io8. 

The vertical projection a" A^' above the I.L. and the 
horizontal projection aJ" 3'' below the I.L. both in the same 
straight line. 

In mechanical drawing the vertical projection a" is called 
the Elevation and the horizontal projection a!' the Plan. 

The projections of a line are found in a similar manner, 
by first finding the projections of the two ends of the line, 
and joining them with a straight line. 

Let ab be a line in space si'Mong, parallel to the V.P. 
and perpendicular to the H.P. One end is resting on the 
H.P. 2f ^ from the V.P. 

The points a and b will be vertically projected in the 
points a" and b" . Join a^'b'" . a'"b'" is the vertical projection of 
the line ab. 

When a line is perpendicular to one of the planes of pro- 
jection, its projection on that plane is a point, and the projec- 
tion on the other plane is a line equal to the line itself. 

ab. Fig. 107, is perpendicular to the H.P., therefore its 
proj. on the H.P. when viewed in the direction ab will be 
seen to be a point. 



OR THOGRA PHIC PR OJE C TION. 



n 



Conceive now the V.P. revolved as before, the V. proj. 
will be found to be at a'^b'"^ Fig. io8, and the H. proj. at the 
point a^. 

cd, Fig. 107, is a line parallel to the H.P. and perpendic- 
ular to the V.P. Its elevation or V. proj. is the point d''\ Fig.. 
108, and its plan or H. proj. the line rV^' perpendicular to 
the Intersecting Line and equal in size to the line itself. 

Planes or Plane Surfaces bounded by lines are projected 
by the same principles used to project lines and points. 

Let aa"b'"b, Fig. 107, be a plane at right angles to and 
touching both planes of projection. 

The elevation of the front upper corner a is projected in 
the point a" . The elevation of the front lower corner b is pro- 
jected in the point b'" . Join d"b'" . a"b'" is the vertical projection 
of the front edge ab of the plane. The plan of the front 







V 




V 


V 


a 




a 
I 


d 














C 




V 












b 


h 












c 










h 

a, 


d 







Fig. 108. 

Upper corner is projected in the point b and the point (f in the 
point b"". A straight line joining bb"" is the plan or horizontal 
projection of the top edge of the plane. 

On the drawing-paper the plan and elevation of the i)lane 
aa"b a would be shown as a continuous straight line if' to a^' 
Fig. 108. 



78 



MECHANICAL DRA WING. 



Solids bounded by plane surfaces are projected by means 
of the same principles used to project planes, lines, and points. 

C, Fig. 107, is a cube bounded by six equal sides or sur- 
faces. The top and bottom being parallel to the H.P. and 
the front and back parallel to the V.P., the vert. proj. is a 
square above I.L. equal in area to any one of the six faces 
of the cube. The hor. proj. is a similar square below I.L. 

These projections are shown at C^ Fig. 108, as they would 
appear on the drawing-paper. 

The foregoing illustrates a few of the simple principles of 
projection in relation to points, lines, and solids when placed 
in the first dihedral angle, and we find that the plan is always 
below and the elevation always above the I.L. 

Let us now consider the same problems when situated in 
the tJiird angle. The point a, Fig. 109, is behind of the V.P. 




Fig. 109. 



and below the H.P. Draw through a perpendiculars to the 
plane of projection. The Hor. proj. is found at c^ and the 
vert. proj. at a" . 

Conceive again the V.P. to be revolved in the direction 
of the arrow until it coincides with the H. P. The hor. proj. 



ORTHOGRAPHIC PROJECTION, 



79 



will then appear at a!' above the I.L. and the vert. proj. at a" 
below the I.L., Fig. no. And so with the lines, the planes, 
and the solids. 



K 


d" ^^ 






«■ 




C 






h 










». 


C 






















V 


u 


V 




a 


a- 





Fig. iio. 



In order to still further explain the use of the planes of 
projection, with regard to objects placed in the third angle, 
let us suppose a truncated pyramid surrounded by imaginary 
planes at right angles to each other, as shown by Fig. in. 




Fig. III. 

With a little attention it will easily be discerned that the 
pyramid is situated in the third dihedral angle, and that in 
addition to the V. and H. planes, we have passed two profile 
planes at right angles to the V. and H. planes, one at the right- 
hand and one at the left. 

When the pyramid is viewed orthographically through 
each of the surrounding planes, four separate views arc had, 



8o 



ME CHA NIC A L DRA WING. 



exactly as shown by the projections on the opposite planes', 
viz., a Front View, Elevation, or Vert. Proj. at F. ; a Right- 
hand View, Right-end Elevation, or Right-profile Projection 
at R. ; a Left-hand View, Left-end Elevation, or Left-profile 
Projection at L. ; a Top View, Plan or H. Proj. at P. 

If we now consider the V.P. and the right and left profile 
planes to be revolved toward the beholder until they coincide, 
using the front intersecting lines as axes, the projections of the 
pyramid will be seen as shown by Fi»g. 1 12, which when the 



1 // 


-^""^ 


P 




$x 


^--^"^ 




\ / 












I 












/ 




\ 








i 


{( 














"\ 


^ 


^ 


\ 


\ 
































1 


\ 






/ 


\ 






/ 


\ 




L 


F 


R 





Fig. 112. 



imaginary planes and projecting lines have been removed, will 
be a True Drawing or Orthographic Projection of the truncated 
pyramid. 

NOTATION. 

In the drawings illustrating the following problems and 

their solutions the given and required lines are shown wide and 

black. Hidden lines are shown broken into short dashes a little 

'narrower than the visible lines. Constructioji or projection lines 

are drawn with very narrow full or continuous black lines. 



ORTHOGRAPHIC PROJECTION. Si 

When convenient very narrow, continuous blue lines are some- 
times used. 

The Horizontal Plane is known as the H.P., the Vertical 
Plane as V.P. and the Profile Plane as Pf.P. 

A point in space is designated by a small letter or figure, 
their projection by the same letters or figures with small // or 
V written above for the horizontal or vertical projection re- 
spectively. 

In some complicated problems where points are designated 
by figures their projections are named by the same figures 
accented. 

Drawings should be carefully made to the dimensions 
given, the scale to be determined by the instructor. 

The student should continually endeavor to improve in 
inking straight lines, curves, and joints. 

In solving the following problems the student should have 
a model of the co-ordinate planes for his own use. This can 
be made by taking two pieces of stiff cardboard and cutting a 
slot in the center of one of them large enough to pass the 
folded half of the other through it ; when unfolding this half a 
model will be had like that shown by Fig. 107 or 109. 

All projections shall now be made from the third, 
dihedral angle. 

Prob. I. — A point a is situated in the third dihedral 
angle, \" below the H.P. and i" behind the V.P. 

It is required to draw its vertical and horizontal projec- 
tions. 

Draw a straight line a!Ui" , Fig. 113, perpendicular to I.L. 
and measure off the point a" \" below I.L. and the point (/'' 
3" above I.L. 



S2 



MECHANICAL DRAWING. 



a'' is the vertical and a!' the horizontal projection in the 
same straight line a"a!'. 

The student should demonstrate this with his model. 

Prob. 2. — Draw two projections of a line 3'Mong parallel 
to both planes, I" below the H.P. and 2" behind the V.P. 

As the line is parallel to both planes, both projections will 
be parallel to the I.L. 

Draw a't'' the vert. proj. of the line ^" long, Fig. 1 14, par- 
allel to I.L. and i" below it. Draw the hor. proj. 2" above 
the I.L. and parallel to it, making it the same length as the 



A 


i 




b 

a 


/ 


/ 


a 


K 
1 




h 


A. 

h. 


' 


a 

c 


b 


h 




\ ^ 


y^ 










\ 








a 






T 




t 






a 




«•," 




d 




bi 




i* 




b' 




^vN^ t 




a 




a,^ 


h 


""X.^^ 


/ i 



Fig. 113. Fig. 114. Fig. 115. Fig. 116. 



Fig. 117. 



vert. proj. by drawing lines perpendicular to I.L. from the 
points a^ and b"" to a^' and b^\ 

Prob. 3. — To draw the hor. and vert, projs. of a straight 
line 3'' long, per. to the vert, plane, Fig. 115. 

As the line is per. to the- vert, plane the vert. proj. will be 
a point below the I.L. and the hor. proj. will be parallel to 
the horizontal plane and per. to I.L. 

Prob. 4. — To draw the plan and elevation of a straight 
line 6'^ long making an angle of 415° with the vert, plane and 
and par. to the hor. plane. Fig. 116. 



ORTHOGRAPHIC PROJECTION. 83 

The plan or hor. proj. will be above the I.L. and make an 
angle of 45° with it. The elevation or vert. proj. will be 
below and par. to I.L. 

Draw from the point a!' at any convenient distance from 
I.L. a straight line a^V" 6" long, making an angle 4$° with I.L, 

Draw a"b'' par. to I.L. at a convenient distance below it. 
The length of the elevation or vert. proj. is determined by 
dropping perpendiculars from the end of the hor. proj. a^'b^'' to 
the points a^b" . 

Prob. 5, Fig. 117. — To find the true length of a straight 
line oblique to both planes of projection and the angle it 
makes with these planes. 

a"b'" and a'^b^' are the projections of a straight line oblique 
to V.P. and H.P. Using a" as a pivot, revolve the line a"b'" 
until it becomes parallel to I.L. as shown by a'^'b^^. From the 
point by'' erect a per. Through the point ^^ draw a line par. to 
I.L. cutting the per. in the point b^\ 

The broken line a''b^' is the true length of the line ab, 
and the angle is the true angle which the line makes with 

V.P. 

To find the angle it makes with H.P. : 

Using b'' as a pivot, revolve the line b^a!" until it becomes 
par. to I.L. as shown by b^'a^^. From the point a^'' drop a per. 
Through the point a" draw a line par. to I.L. intersecting the 
per. at the point a^o is the angle which the line ab makes 
with H.P. and the broken line a^^b" is again its true length. 

Prob. 6, Fig. 118. — To project a plane surface of given 
size, situated in the third angle and par. to the V.P. 

Let abed be the plane surface i" long X 2" wide. If 
we conceive lines to be projected from the four corners of the 



84 MECHANICAL DRAWING. 



1 



plane surface to the V.P. and join them with straight hnes we 
will have its V. projection a'"b'"c"d'" and shown b}^ Fig. Ii8. 
And as the plane surface is par. to the V P. it must be per 
to the H.P. since the planes of projection are at right angles 
to each other. So the plan or H. projection will be a straight 
line equal in length to one of the sides of the plane surface. 

At a convenient distance above I.L. draw a straight line, 
and from the points rt";^'' project lines at right angles to I.L., 
cutting the straight line in the points a^'bJ' The line a^b'' is 
the hor. proj. of the plane surface abed. 

PrOB. 7, Fig. ii8. — To draw the projections of a plane 
surface of given dimensions when situated in the third angle 
perpendicular to the H.P. and making an angle with the V.P. 

Let the plane surface be 3" X 2'' as before and let the 
angle it makes with V.P. be 60°. 

To draw the plan : 

At a convenient distance above I.L. and making an angle 
of 60° with it, draw a^'b^\ Fig. 118, 2" long. From b,^' drop a 
per. cutting a"b'" in the point ^j" and r'^" in the point d^\ then 
the rectangle d'b^d^c" will be the vert. proj. or elevation of 
the plane surface abed. 

Prob. 8, Fig. 119. — To draw the projections of the same 
plane surface (i) w^hen parallel to the H.P., (2) when making 
an angle of 30° with H.P. and per. to V.P., (3) when mak- 
ing an angle of 60° with H.P. and per. to V.P., and (4) when 
per. to both planes. 

Fig. 119 shows the projections; further explanations are 
unnecessary. ^ 

Prob. 9, Figs. 119 and 120. — To draw the projections of 



ORTHOGRAPHIC PROJECTION. 



85 



the same plane surface when making compound angles with 
the planes of projection. 

Let the plane make an angle of 30° with H.P., as in the 
second position of Prob. 8, Fig. 119, and in addition to that, 
revolve it through at angle of 30°. First, draw the plane 
parallel to H.P., as shown by a!'d'b^'d^, Fig. 119, the true size 
of the plane. 




Fig. 119. Fig, 120. 

Its elevation will be the straight line a^'b" parallel to I.L. 
Next revolve a^b" ^ using a' as a pivot, through an angle of 
30°, to the position d"b^\ which is its vert. proj. when making 
an angle of 30° with H.P. Its plan is projected in a'' b I' c'' d ^' . 

Now as the plane is still to make an angle of 30° with 
H.P. after it has been revolved through an angle of 30° with 
relation to the V.P., its hor. proj. will remain unchanged. 

With a piece of celluloid or tracing-paper trace the hor. 
proj. a''bl'c''d'\ lettering the points as shown, and revolve the 



86 MECHANICAL DRAWING. 

tracing through the angle of 30°, or, which is the same thing, 
place the tracing so that the line (^V' will make an angle of 
60° with I.L., and with a sharp conical-pointed pencil trans- 
fer the four points to the drawing-paper and join them by 
straight lines, as shown by Fig. 120. 

And as the line al'd' retains its position relative to H.P. 
after the revolution, its elevation will be found at d'c'. Fig. 
120, in a straight line drawn through cfb''^ Fig. 119, intersect- 
ing perpendiculars from a!'(^\ Fig. 120. And the vert. proj. 
of the points bl'dl' will be found at h^"d^% Fig. 120, in a straight 
line drawn through b^^, Fig. 119, parallel to I.L. and intersect- 
ing pers. from bl'dl\ join with straight lines the points 
d"b:'dd,\ 

Draw the projections of the plane when making an angle 
of 60° with H.P. and revolved through an angle of 30° with 
relation to V.P. 

Draw the projections of the plane when making an angle 
of 60° with the V.P. and per. to the H.P., Fig. 120. 

Prob. 10. — To draw the projections of a plane surface of 
hexagonal form in the following positions: (i) When one 
of its diagonals is par. to the V.P. and making an angle of 
45° with the H.P. (2) When still making an angle of 45° 
with the H.P. the same diagonal has been revolved through 
an angle of 60^. 

Draw the hexagon i ^'2 ^'3 ^'4^ 5 ^'6'', Fig. 121, at any con- 
venient distance above I.L., making the inscribed circle 
= 2^'\ This will be its hor. proj. and 2''4*6''i^ its vert, proj,, 
the diagonal V'2^ being par. to both planes of proj. With 
I" as an axis revolve 6''4''2'' through an angle of 45°. Through 
the points 2j*4j^6,'' erect pers. to the points 6,^5,^4,^3,^ ^i^d 2,* 



ORTHOGRAPHIC PROJECTION. 



87 



and join them with straight Hnes. These are the projs. in 
the first position. Now trace the hor. proj, \^\ 2/', etc., ort 
a piece of celluloid or tracing-paper and revolve the tracing 
until the diagonal i^'2/' makes an angle of 60° with the I.L., 
Fig. 122. Next draw pers. from the 6 points of the hexag- 
onal plane to intersect hors. from the corresponding points of 
the elevation in Fig. 121, join the points of intersection with 




Fig. 122. 

straight lines, and so complete the projections of the second 
position. Fig. 122. 

Prob. II, Figs. 123 and 124. — Draw the projs. of a cir- 
cular plane (i) when its surface is par. to the vert, plane, (2) 
when it makes an angle of 45° with the V.P., and (3) when 
still making an angle of 45° with the V.P. it has been re- 
volved through an angle of 60°. 

First position: Draw the circular plane i", 2", 3", 4", etc., 
Fig. 123, below the I.L. with a radius = \^' and divide and 
figure it as shown. 



S8 



ME CHA NTCA L DRA J fVXG. 



Since the plane is par. to V.P. its hor. proj. will be a 
straight line i\ 2^' etc. 

For the second position revolve the said hor. proj. through 
the required angle of 45° to the position a'' . . . . i/\ Fig. 123, 
and through each division in i'' .... a'' draw arcs cutting 
^'' . . . . i'' in points 2''^^'' . . . This is the hor. proj. of the 
plane when making an angle of 45° with the V.P. 

The elevation is found by dropping pers. from the points 
in the hor. proj. a^' . . .ij^ to intersect hor. lines drawn 
through the correspondingly numbered points in the eleva- 




FiG. 123. 



tion and through these intersections draw the elevation or 

vert. proj. of the second position. 

For the third position make a tracing of the elevation of 
the second position, numbering all the points as before, and 
place the tracing so that the diameter /'"/'' makes the required 
angle of 60° with the I.L. and transfer to the drawing-paper. 



ORTHOGRAPHIC PROJECTION. 89 

The result will be the elevation of the third position shown 
below the I.L., Fig. 124. Its hor. proj. is found by drawing 
pers. through the points i, 2, 3,4 ... to intersect hors. drawn 
through the corresponding points in the hor. proj. of the 2d 
position and through these intersections draw the plan or hor. 
proj. of the third position, Fig. 124. 

Prob. 12, Fig. 125. — Draw the projs. of a regular hexag- 
onal prism, ^" high and having an inscribed circle of ^%" 
diam. : (i) When its axis is par. to the V.P. (2) Draw the 
true form of a section of the prism when cut by a plane 
passing through it at an angle of 30° with its base. (3) 
Draw the projection of a section when cut by a plane passing 
through XX, Fig. 125, per. to both planes of proj. 

The drawing of the I.L. may now be omitted. 

For the plan of the first part of this prob. draw a circle 
with a radius == to 2-f-^" , and circumscribe a hexagon about it, 
as shown by a!\ b^\ b^\ etc., Fig. 125. To project the elevation, 
draw at a convenient distance from the plan a hor. line par. 
to a^d'\ and ^" below it another line par. to it. From the 
points a!'y'(^'d^\ drop pers. cutting these par. lines in the points 
a"b'"c'"d'", thus completing the elevation of the prism. 

Second condition : Draw the edge view or trace of the 
cutting plane i'^' , making an angle of 30° with the base of the 
prism, locating the lower end 4.' one-half inch above the base; 
parallel to i'^!, and at a convenient distance from it draw a 
straight line 1,4; at a distance of 2^\" on each side of 1,4 
draw lines 3, 2 and 5, 6 parallel to 1,4, and through the 
points i'2'3V let fall pers. cutting these three par. lines in 
the points i, 2, 3, 4, 5, 6; join these points by straight lines 



90 



MECHAXICAL DRAWIXG. 



as shown, and a true drawing of the section of the prism as 
required will result. 

For the third condition of the problem : 

Let XX be the edge view of the cutting plane and con- 
ceive that part of the prism to the right of XX to be removed. 

h c 



I 




Fig. 125. 



Fig. 126. 



From the hor. proj. of the prism draw a right-hand elevation 
or profile proj., and through the points XX draw the lines en- 
closing the section, and hatch-line it as shown. 

Prob. 13. — To draw the development of the lower part 
of the prism m the elevation of the last problem. 



ORTHOGRAPHIC PROJECTION. Qf 

To the right of the elevation in Fig. 125, prolong the base- 
line indefinitely and lay off upon it the distances ab, be, cd, 
etc., Fig. 126, each equal in length to a side of the hex. At 
these points erect pers., and through the points i'2'3'4' draw 
hor. lines intersecting the pers. in 4, 3, 2, i, etc. At be 
draw the hex. a^^b'^b'^^c^'c'^^d'' of the last prob. for the base, and 
Sit I, 2 draw the section i, 2, 3, 4, 5, 6 for the top. 

PkOB. 14, Fig. 127. — To draw the projs. of a right cylin- 
der 3'' diam. and 3'' long, (i) When its axis is per. to the 
H.P. (2) Draw the true form of a section of the cylinder, 
when cut by a plane per. to the V.P. making an angle of 30° 
with the H.P. (3) Draw a development of the upper part of 
the cyl. 

For the plan of the first condition, describe the circle \\ 
2', etc., with a radius = ih;' and from it project the eleva- 
tion, which will be a square of ^" sides. 

For the second condition: Let i, 7 be the trace of the 
cutting plane, making the point 7, ^" from the top of the cyl. 
Divide the circle into 12 equal parts and let fall pers. through 
these divisions to the line of section, cutting it in the points 
I, 2, 3,4, etc. Parallel to the line of section i, 7 draw i"j" 
at a convenient distance from it, and through the points 
1, 2, 3, 4, etc., draw pers. to i, 7, intersecting and extending 
beyond i"'/". Lay off on these pers. the distances 6 8' — 
6'8', and S^'q'^ = 59, etc., and through the points 2", 3", 
4", etc., describe the ellipse. 

For the development: In line with the top of the ele\a- 
tion draw the line ^'^" equal in length to the circumference of 
the circle, and divide it into 12 equal parts a', b\ etc., a\ b" , 
etc. Through these points drop pers. and through the jooiiits 



92 



MECHANICAL DRA WING. 



I, 2, 3, etc., draw hors. intersecting the pers. in the points I 
J, 2, 3, etc., and through these points draw a curve. 

Tangent to any point on the straight line draw a 3" circle 
for the top of the cyl. and tangent to any suitable point on 
.the curve transfer a tracing of the ellipse. 

Prob. 15, Fig. 128. — Draw the projections of a right cone 
"]" high, with a base 6'' in diam., pierced by aright cyl. 2" in 




Fig. 127. 

diam. and 5'' long their axes intersecting at right angles 3" 
above the base of the cone and par. to V.P. Draw first the 
plan of the cone with a radius = 3''. 

At a convenient distance below the plan draw the elevation 
to the dimensions required. 

3" above the base of the cone draw the center line of the 
cyl. CD, and about it construct the elevation of the cyl., which 
will appear as a rectangle 2" wide and 2\" each side of the 
axis of the cone. The half only appears in the figure. 



ORTHOGRAPHIC FROJECriON. 



93 



To project the curves of intersection between the cyl. and 
cone in the plan and elevation : Draw to the right of the cyl. 
on the same center line a semicircle with a radius equal that 
of the cyl. Divide the semicircle into any number of parts^ 




Fig. 128. 



Fig. 129. 



as I, 2, 3, 4, etc. Through i, i draw the per. A" \" equal 
in length to the height of the cone, and through A" draw the 
\ineA"4" tangent to the semicircle at the point 4, and through 
the other divisions of the semicircle draw lines from A" to the 
line i"4", meeting it in the points 3"2''. 

From all points on the line i"4", viz., r'2"3"4", erect 



94 MECHANICAL DRAWING. 

pers. to the center line of the plan, cutting it in the points 
.i,''2/'3/'4,'', and with i/^ as the center draw the arcs 2/^-2, 
3/'-3, 4/'-4 above the center Hne of the plan, and through the 
points 2, 3, 4 draw hors. to intersect the circle of the plan in 
the points 2'3^4^ and lay off the same distances on the other 
side of the center line of the plan in same order, viz., 2' i' a^ . 
Through each of these points on the circumference of the circle 
of the plan draw radii to its center A' , and through the same 
points also in the plan let fall pers. to the base of the elevation 
of the cone, cutting it in the points 2' i' \ ; and from the apex 
A of the elevation of the cone draw lines to the points 2^3 4' on 
the base. Hor. lines draw^n through the points of division 2, 
3, 4 on the semicircle will intersect the elements A-2\ A-^\ 
A-4 of the cone in the points 2'3'4'; these will be points in 
the elevation of the curve of intersection between the cylinder 
and the cone. 

The plan of the curve is found by erecting pers. through 
the points in the elevation of the curve to intersect the radial 
lines of the plan in correspondingly figured points, through 
which trace the curve as shown. Repeat for the other half 
of the curve. 

Prob. 16, Fig. 129. — To draw the development of the 
half cone, showing the hole penetrated by the cyl. 

With center 4/', Fig. 129, and element Ai^ of the cone, 
Fig. 128, as radius, describe an arc equal in length to the semi- 
circle of the base of the cone. Bisect it in the line 4/^1, and 
on each side of the point i lay off the distances 2, 3, 4, equal 
to the divisions of the arc in the plan Fig. 128, and from these 
points draw lines to 4", the center of the arc. Then with 
radii A-a, b, c, d, e, respectively, on the elevation Fig. 128, 



OR THOGRA PHI C PR OJE CTION, 



95 



and center 4/' draw arcs intersecting the lines drawn from the 
arc XX to its center 4/'. Through the points of intersection 
draw the curve as shown by Fig. 129. 

Prob. 17, Fig. 130. — To draw the development of the 
half of a truncated cone, given the plan and elevation of 
the cone. 




Fig. 130. 

Divide the semicircle of the plan into any number of parts, 
then with A as center and A i as radius, draw an arc and lay 
off upon it from the point i the divisions of the semicircle 
from I to 9, draw ()A. Then with center y^ and radius AB 
draw the arc BC. \BC<^ is the development of the half of 
the cone approximately. 



96 



ME CHA NI CA L DRA WING . 



Prob. 1 8, Fig. 131. — To draw the curve of intersection of 
a small cyl. with a larger. To the left of the center-line of 
Fig. 131 is a half cross-section, and to the right a half eleva- 
tion of the two cyls. 

Draw the half plan of the small cyl., which will be a 
semicircle, and divide it into any convenient number of parts, 
say 12. 

From each of these divisions drop pers. 

On the half cross-section these pers. intersect the circum- 
ference of the large cyl. in the points i\ 2', etc. Through 



Fig. 134. 



Fig. 133. 



Fig. 151. 




Fig. 132. 



these points draw hors. to intersect in corresponding points 
the pers. on the half elevation. Through the latter points 
draw the curve of intersection C. 

Prob. 19. — To draw the development of the smaller cyl. 
of the last prob. 

Draw a rectangle, Fig. 132, with sides equal to the circum- 



ORl^HOGRAPHIC FROJECTION. 97 

ference and length of the cyl. respectively, and divide it into 
24 equal parts. 

Make AB, i i', 3 3', etc., Fig. 132, equal to AB, \'i'\ 
2^2^', 3'3'', etc., Fig. 131, and draw the developed curve of 
intersection. 

PrOB. 20. — To draw the orthographic projections of a 
cylindrical dome riveted to a cylindrical boiler of given 
dimensions. 

Let the dimensions of the dome and boiler be : dome 
2^\" diam. X 2j" high, boiler 54^^ diam., plates J'' thick. 

Apply to the solution of this problem the principles ex- 
plained in Prob. No. 18, Fig. 131. 

When your drawings are completed, compare them with 
Figs. 133 and 134, which are the projections required in the 
problem. 

Letter or number the drawing and be prepared to explain 
how the different projections were found. 

Prob. 21. — To draw the development of the top gusset- 
sheets of a locomotive wagon-top boiler of given dimensions. 

First draw the longitudinal cross-section of the boiler to 
the dimensions given by Fig. 135, using the scale of i" = 
I ft. 

Then at any convenient point on your paper draw a 
straight line, and upon it lay off a distance AB 35^" lo"^ = 
the straight part of the top of the gusset-sheet G, Fig. 135. 
With center A and a radius = 2^]^' (the largest radius of the 
gusset) -|- 6" (the distance from the center of the boiler to the 
center of the gusset C, Fig. 135} = 33f , draw arc i. 

With'center^ and a radius r= 26J" (the smallest radius of 
the gusset) draw arc 2. Tangent to these arcs draw the 



98 



ME CHA NJ CA L DKAWIAG. 



straight line i, 2 extended, and through the points^ and 
draw lines i, A and 2, B per. to i, 2. 



a 




Take a point on the per. i, 2, 6" from the point i as a 
center and through the point A draw an arc with a radius 



— -yn^" 



ORTHOGRAPHIC PROJECTION. 99 

vVith point 2 as a center and 2B as a radius [26^") draw 
an arc through B to meet the Hne 1,2. 

Divide both arcs into any number of parts, say 12, and 
through these divisions draw Hnes per. to and intersecting \A 
and 2B respectively. Through these intersections draw in- 
definite hors. and on these hors. step off the length of the 
arcs, with a distance = one of the 12 divisions as follows: 

On the first hors. lay off the length of the arc A\' and B\' 
— y4 I and B\ respectively. Then from i' lay off the same 
distance to 2' on the second hors. etc. Through these points 
•draw curves A\^' and B12'. Join points 12' and 13^ with a 
straight line Then AB12, 13 will be the developed half of 
the straight part of the gusset. 

On the two ends or front and back of the gusset we have 
now to add i'^ for clearance -|- 3i' ^oi' lap -|- |-" allowance 
for truing up the plates, total — 5J". And to the sides 2-|'^ 
for lap -|- ¥^ allowance for truing up, total = 3-§-''. 

The outline of the developed sheet may now be drawn to 
include these dimensions with as little waste as possible, as 
shown by Fig. 136. Extreme accuracy is necessary in mak- 
ing this drawing, as the final dimensions must be found by 
measurement. 

Prob. 22. — To draw the projections of a V-threaded 
screw and its nut of 3" diam. and f pitch. 

Begin by drawing the center line C, Fig. 137, and lay off 
on each side of it the radius of the screw i^". Draw AB 
and 6D. Draw A6 the bottom of the screw, and on AB step 
off the pitch = f'^ beginning at the point A. 

On line 6D from the point 6 lay off a distance = half the 
pitch =: f, because when the point of the thread has com- 



lOO 



ME CHA Nl CAL DRA WING . 



pleted half a revolution it will have risen perpendicularly a 
distance = half the pitch, viz., f'^ 

Then from the point 6" on 6D step off as many pitches as 
may be desired. From the points of the threads just found, 

B D 





Fig. 137. Fig. 138. 

draw with the 30° triangle and T-square the V of the threads 
intersecting at the points b . . b . . the bottom of the threads. 

At the point O on line A6 draw two semicircles with radii 

II the top and bottom of the thread respectively. Divide 

these into any number of equal parts and also the pitch Pinto 

the same number of equal parts. Through these divisions 

draw hors. and pers. intersecting each other in the points as 



ORTHOGRAPHIC PROJECTION. 



lOI 



shown by Fig. 137, which shows an elevation partly in section 
and a section of a nut to fit the screw. Through the points 
of intersection draw the curves of the helices shown, using 
No. 3 of the "" Sibley College Set " of Irregular Curves. 




Fk;. 139. 

Prob. 22. — To draw the proj. of a square-threaded screw 
3'' diam. and \" pitch and also a section of its nut. 

The method of construction is the same as for the last 
problem, and is illustrated by Fig. 138. 

Prob. 22. — To draw the projections of a square double 
threaded screw of 3" diam. and 2" pitch, and also a section of 
its nut. 



I02 



MECHANICAL DRA WING. 



The solution of this problem is shown by Fig. 139, and 
further explanation should be unnecessar}-. 

Prob. 23. — To draw the curve of intersection that is 
formed by a plane cutting an irregular surface of revolution. 




Fig. 140. 

Figs. 140, 141, and 142 show examples of engine con- 
necting rod ends where the curve / is formed by the inter- 



©qi 



"^ 




Fig. 141. 

section of the flat stub end with the surface of revolution ci 
the turned part of the rod. 



OR THOGRA PHIC PROJECTION. 



103 



The method of finding the curves of intersection are so 
plainly shown by the figures that a detailed explanation is 
deemed unnecessary. 




Fig. 142. 



SHADE LINES, SHADES AND SHADOWS. 

Shade Lines are quite generally used on engineering work- 
ing drawings; they give a relieving appearance to the projec- 
ting parts, improve the looks of the drawing and make it easier 
to read, and are quickly and easily applied. 

The Shading of the curved surfaces of machine parts is 
sometimes practiced on specially finished drawings, but on 
working drawings most employers will not allow^ shading be- 
cause it takes too much time, and is not essential to a quick 
and correct reading of a drawing, especially if a system of 
shade lines is used. 

Some of the principles of shade lines and shading are 
given below, with a few problems illustrating their commonest 
applications. 

The shadows which opaque objects cast on the planes of 



104 MECHANICAL DRAWING. 

projection or on other objects are seldom or never shown on 
a working drawing, and as the students in Sibley College are 
taught this subject in a course on Descriptive Geometry, it is 
omitted here. 

CONVENTIONS. 

The Source of Light is considered to be at an infinite dis- 
tance from the object, therefore the Rays of Light will be rep- 
resented by parallel lines. 

The Source of Light is considered to be fixed, and the Point 
■of Sight situated in front of the object and at an infinite dis- 
tance from it, so that the Visual Rays are parallel to one 
another and per. to the plane of projection. 

Shade Lines divide illuminated surfaces from dark surfaces. 

Dark surfaces are not necessarily to be defined by those 
isurfaces which are darkened by the shadow cast by another 
part of the object, but by reason of their location in relation 
to the rays of light. 

It is the general practice to shade-line the different pro- 
jections of an object as if each projection was in the sam.e 
plane, e.g., suppose a cube. Fig. 143, situated in space in the 
third angle, the point of sight in front of it, and the direction 
•of the rays of light coinciding with the diagonal of the cube, 
as shown by Fig. 144. Then the edges ^^^^^ b^c" will be shade 
lines, because they are the edges which separate the illumin- 
ated faces (the faces upon which fall the rays of light) from 
the shaded faces, as shown by Fig. 144. 

Now the source of light being fixed, let the point of sight 
remain in the same position, and conceive the object to be re- 
t/olved through the angle of 90° about a hor. axis so that a 



OR THO G RA PHIC PR OJE C Tl ON. 



105 



plan at the top of the object is shown above the elevation, and 
as the projected rays of Hght faUing in the direction of the 
diagonal of a cube make angles of 45° with thehor., then with 
the use of the 45° triangle we can easily determine that the 
lower and right-hand edges of the plan as well as of the ele- 
vation should be shade lines. 

This practice then will be followed in this work, viz. : 
Shade lines shall be applied to dX\ projections of an object, 



Fig. 143. 




Fig. 144. 



considering the rays of light to fall upon each of them, from 
the same direction. 

Shade lines should have a width equal to 3 times that of 
the other outlines. Broken lines should never be shade lines. 

The outlines of surfaces of revolution should not be shade 
lines. The shade-lined figures which follow will assist in il- 
lustrating the above principles; they should be studied until 
understood. 



I06 MECHANICAL DRA WING. 



SHADES. 



The sJiade of an object is that part of the surface from 
which Hght is excluded by the object. 

The line of sJiade is the Hne separating the shaded from 
the illuminated part of an object, and is found where the rays 
of light are tangent to the object. 

Brilliant Points. — " When a ray of light falls upon a sur- 
face which turns it from its course and gives it another direc- 
tion, the ray is said to be reflected. The ray as it falls upon 
the surface is called the incident ray, and after it leaves the 
surface the reflected ray. The point at which the reflection 
takes places is called the point of incidence. 

" It is ascertained by experiment — 

" (a) That the plane of the incident and reflected rays is 
always normal to the surface at the point of incidence; 

'* (d) That at the point of incidence the incident and re- 
flected rays make equal angles with the tangent plane or normal 
line to the surface. 

" If therefore we suppose a single luminous point and the 
light emanating from it to fall upon any surface and to be re- 
flected to the eye, the point at which the reflection takes place 
is called the brilliant point. The brilliant point of a surface 
is, then, the point at which a ray of light and a line drawn to 
the eye make equal angles with the tangent plane or normal 
line — the plane of the two lines being normal to the surface." 
— Davies : SJiades and Shadoivs. 

Considering the rays of light to be parallel and the point 
of sight at an infinite distance, the brilliant point on the sur- 
face of a spJiere is found as follows: Let A'"C'" and A''0\ Fig. 



OR 'J -HO G RA PHIC PR OJE C TION. 



107 



145, be a ray of light and A'"A^' a visual ray. Bisect the angles 
contained between the ray of light and the visual ray as fol- 
lows : Revolve A'"C'" about the axis A'" until it becomes parallel 
to the hor. plane at A'"C^' . At C^ erect a per. to intersect 
a hor. through C^ at CI' join Cl'L!" {L may be any convenient 




Fig. 145. 



point on the line of vision), bisect the angle Z''^^'^'/' with the 
line A^'iy\ Join C'L' and through the point Z^', draw a hor. 
cutting C'V' at Dl\ then A^'D^' is the hor. projection of the 
bisecting line. A plane drawn per. to this bisecting line and 
tangent to 'the sphere touches the surface at the points 
B'"Bl' where the bisecting lines pierce it. Therefore B'B^' are 
the two projections of the brilliant point. 



io8 



MECHANICAL DRAWING. 



The point of shade can be found as follows: 
Draw A''G, Fig. 145, making an angle of 45° with a hor. 
Join the points E and /'with a straight line EF. Lay off on 
A''G a distance equal to EF, and join EG. Parallel to EG 
Fig. 146. Fig. 147. 




Fig. 148. 
draw a tangent to the sphere at the point T. Through T 
draw TP^ per. to A^'G. From the point P' drop a per. to P^ 
P^ is the point of shade. 

Prob. 24. — To shade the elevation of a sphere with graded 
arcs of circles. 



ORTHOGRAPHIC PROJECTION. lOg 

First find the brilliant point and the point of shade, and 
divide the radius i, 2 into a suitable number of equal parts, 
and draw arcs of circles as shown by Fig. 146, grading them 
by moving the center a short distance on each side of the 
center of the sphere on the line B^'2 and varying the length of 
the radii to obtain a grade of line that will give a proper 
shade to the sphere. It is desirable to use a horn center to 
protect the center of the figure. 

Fig. 149 shows the stippling method of shading the 
sphere. 





Fig. 149. Fig. 150. 

Prob. 25.— To shade a right cylinder with graded right 
lines. 

Find the line of light E" by the same method used to find 
the brilliant point on the sphere, except that the line of light 
is projected from the point B^' where the bisection line A^'D 
cuts the circle of the cylinder. 

The line of shade is found where a plane of rays is tan- 
gent to the cyl. at S" and S\ 

Fig. 150 shows how the shading lines are graded from 
the line of shade to the line of light. 

It will be noticed that the lines grow a little narrower to 
the right of the line of shade on Fig. 150; this shows where 



no 



MECHANICAL DRA WING. 



the reflection of the rays of light partly illumine the outline 
of the cylinder. 

Prob. 26, Fig. 148. — To shade a right cone with graded 
right lines tapering toward the apex of the cone. 

Find the elements of light and shade as shown by Fig. 148, 
and draw the shading-lines as shown by Fig. 151, grading 
their width toward the light and tapering them toward the 
apex of the cone. 





Fig. 151. 



Fig. 152. 



The mixed appearance of the lines near the apex of the 
cone on Fig. 151 can usually be avoided by letting each line 
dry before drawing another through it, or as some draftsmen 
do, stop the lines just before they touch. 

Prob. 27. — To shade the concave surface of a section of a 

hollow cylinder. 

Find the element of light 
and grade the shading lines 
from it to both edges as shown 
by Fig. 152. 

Fig. 153. Fig. 153 shows a conven- 

tional method of shading a hexagonal nut. 




ORTHOGRAPHIC PROJECTION. 



Ill 



SHADOWS, 



Let R, Fig. 154, be the direction of the rays of h'ght 
and C an opaque body between the source of light and a 




Fig. 154. 

surface 5. The body C will prevent the rays from passing 
in that direction, and its outline will be projected at D on 
the surface 5. D is the sJiadow of C. 

The line which divides the illuminated portion of the 
surface 5 from the shadow D is called the li}te of s/iadozv. 

Shadow of a Point. — If a line is drawn through a point in 
space in a direction opposite to the source of light, the point 
in which this line pierces the plane of projection is the 
shadow of the point on that plane. 



112 MECHANICAL DRAWING. 

To find the shadow on the H.P. of a point in space in 
the first dihedral angle: ^B 

Let A, Fig. 155, be the point in space, and R the ^^ 
direction of the ray of light; then A^ is the shadow of the 
point A on H.P., and A"A,^^ is the hor. proj. and A'^A,^ the 



Fig. 155. 

vert. proj. of R. B^ is the point where R pierces V when 
prolonged below H.P., and B^ is its hor. proj. in the G.L. 
The projections of R would then be A'B^' and A^B". 

The shadow of a point in F may be found in a similar 
manner. 

SJiadoivs of Right Lines. — The shadow of a right line on 
a plane may be determined by finding the shadows of two of 
its points and joining these by a right line; e.g., the shadow 
of the line ABj Fig. 156, on H.P. is found as follows: 

Through the points A^'B^' draw the rays A^A,^' and B^^B^^ 
to intersect the plane of projection in G.L. in the points A^ 
and ^/ ; from these points drop perpendiculars to meet rays 
drawn through A'^ and B^ in the points A^^ and B/^. A line 
drawn from A/^ to B/^ is the shadow of AB on H.P. 

If a righ tline is parallel to the plane of projection its 
shadow will be parallel to the line itself. 



OR THO GRA PHIC PR OJE C TION. 



113 



If a line coincides with a ray of light, its shadow on any 
surface will be a point. 



» t. 




PROB. 28. — To find the sJiadozv of a right line on V.P\ 
and H.P: 

Let AB, Fig. 157, be the given line. Find the shadows. 











^ 


r 






d 


Y 


y^ 


^ 


\ 




/ 




\ 


\ 


\ 


\ 


^ X 

\<^! 


<5_ 








\ 


\/-' 






/ 


\ 


/ 

K 
/ 


A 

1 


M 






/-^c 


a 











Fig. 157. 



114 



ME CHA NICA L D RA WING . 



of the points A and B by passing rays through each of their 
projections to make angles of 45° with G.L. The shadow of 
A'' on H.P. is found at A,", and that of B'' at B^', where the 
rays through these points intersect the H.P. The shadow 
of ^^ on V.P. is found at A,'^ and that of B^' at B^, where 
the rays through these points intersect V.P. Join A^" and 
^/^ with a straight line and we have the shadow of AB on 
H.P., and the shadow on V.P. is found in the same way by 
joining with a straight line the points A^^ and B^\ 

That part of the shadow which falls on V.P. below G.L., 
and on H.P. above G.L., is called the secondary shadow, 
because it makes a second intersection, i.e., it is conceived 
to have passed through V.P. and made an intersection with 
H.P. behind V.P. With the use of the secondary shadow 
problems like this are easier of solution. 




OR THOGRA PHIC PR OJE C TION. 



lis 



Prob. 29. — ABCD, Fig. ij8, is a sqitare plate parallel to 
V.P. ; find its shadow oji H.P. 

Through the points ^^', B'\ D'\ and A^'C, 3"^", draw 
rays making the angle of 45° (or any other angle which may 
be adopted) with G.L., and determine the shadows of these 
points as explained in Fig. 155. They will be found in the 
points A^B^ , C" , D^^ . Join these points with right lines 
and they will form the line of shadow of the square plate on 
H.P. 

Prob. 30. — To find tJie sJiadozv of a cube 07i V.P. zvith 
one face in V.P. and tJie other faces parallel or perpendicular 
to H.P. 

Fig. 159 shows the cube in the given position. The line 

V V y y 

C A D B 




Fig. 159. 
of shade is composed of edges EF, FGy GD, DB, and the 
edges AE and AB in V.P. which coincide with their shadows. 



Il6 



ME CHA NICA L DRA WING . 



The shadow of EF is E^ F^, of EG is F^ G^, of GD is G^D^, 
of DB is D,B^\ The shadows of the edges AE and .4^ 
coincide with the lines. These shadows are found by the 
same rules used for finding the shadows of a line in Prob. 28. 
The line of shadow is B'^D,G,F,F'E''A'^D'\ The visible line 
of shadow is B''Dfi,F,E''C''D'\ 

Prob. 31. — To find the shadow of a rectangular abacus 07i 
the face of a rectangular pillar. 

Assume the hor. and vert, projs. of the abacus and pillar 
to be as shown in Fie, 160. 




^ If ft 



The line of shade of the abacus is seen to be the edges 
A^'B,"" and A^^'C,''. The plane of rays through edge A.^'B,'^ 
is per. to V.P., and the line A^E^^ is its vert. proj. or trace; 
its hor. trace is A^E^. The shadow on the left side face, is 
vertically projected in the point ^^^ where the plane of rays 
intersects that face. The ray through the point A^ pierces 
the front face in the point E" , which is the shadow of Af^y 



41 



OR 7 HOGRA PHIC PR OJE C 7 lOiW 



117 



md E,"E", E^^'e^ is the shadow of the part F^^A," on this 
face. 

The line A^^^C" is parallel to tlie front face, therefore its 
shadow on it will be parallel to itself and pass through E. 

The visible line of shadow is now found to be i E^ E^ W 2 i. 

Prob. 32. — Construct the shade of an upright hex. prism 
and its shadoiv on both planes. 

Fig. 161 shows the given prism with its line of shade 




Fig 161. 



A,''B,''E,''D''F'' on the vert, proj., C'D'^F^'EJ' on the hor. 
proj., and its shadow on both planes. 

Prob. 33. — Given a circular plate parallel to one coordin- 
ate plane ; construct its sJiadoiv on the other plane. 



Il8 MECHANICAL DRAWING. 

Let^^^^r^/^'^and^^^C'^ Fig. 162, be the projections 
of the circular plate. 

Circumscribe a square j£"^6^^ about the circle; its shadow 
on H.P. will be the parallelogram A"G^^ and the shadows 
of the points A^B^X^^D^ are projected in the points 




Fig. 162. 



A^B"C"D^". The shadow of the inscribed circle is an el 
lipse tangent to the parallelogram at the points A^^B.^'C^D/', 
with B,"D," and A^"C^" as conjugate diameters. 

The position and length of the axes of the ellipse of 
shadow may be found as follows: 

Erect a perpendicular at the point C^ making 6^^j^^ equal 
to radius of the circle' draw KOP\ then KP is equal to the 
major and MK to the minor axis, and angle 6 is twice the 
angle of the transverse axis with the horizontal conjugate 
diam.; i.e., KP is equal to i, 2, MK to 3, 4, and 2, 0,C,'\ 
or angle d, is equal to half KOC ^. 



1 



OR 1 'HO G RA PHIC PR OJE C 7 PON. 



119 



PrOB. 34. — Find the shade of a cylindrical column and 
abacus y and the shadozv of the abacus on the column. 

Let A'^B^'C' 2.nA A''B"C'\ Fig. 163, be the projections 
of the abacus, D^'E^F'' and D'^D'G'F" the projections of 
the column. 




G_^ 



Fig. 163. 

The line of shade on the column is found by passing two 
planes of rays tangent to the column perpendicular to H.P. 
and parallel to the hor. proj. of the ray of light. KL and 
E^^ are the traces of these planes tangent to the column at 
the points Z, and FJ^ and MN the visible line of deepest 
shade on the cylindrical column. 

The deepest line of shade i, 2 on the abacus is found in 
the same way. 

The line of shadow on the column of that portion of the 
lower circumference of the abacus which is toward the source 
of light is found by passing vertical planes of rays, as 3, 4, to 



'I20 



MECHANICAL DRA WING. 



determine any number of points in the line, and joining these 
points by a line as shown in Fig. 163. 

Prob. 35. — Find the shade of an oblique cone and its 
shadoiv on H.P. 




Take the cone as given in Fig. 164. Pass two planes of 
rays tangent to the cone; their elements of contact will be 
the deepest lines of shade. To determine the elements of 
contact draw a ray through C^\ C^ i»s its hor. trace. From 



ORTHOGRAPHIC PROJECTION. 



121 



C" draw lines tangent to the base at D and E\ the lines of 
contact are CE and CD^ and ECD is the line of shade. 

The visible line of shade on H.P. is E^D^^, and on V.P. 
it is CE'\ The shadow on H.P. is E^C^'D'', 

Prob. 36. — To draw a front and end elevation of a rect- 
angular hollow box with a rectangular block on each face, each 
block to have a rectangular opening, and all to be properly 
shade-lined and drawn to the dimensions given on Fig. 165. 

Draw the hor. center line first, and then the vertical center 
line of the end view. About these center lines on the end el- 

FiG. 165. 




Fig. 166. 
evation construct the squares shown and erect the edges of the 
blocks. Next draw the hidden lines indicating the thickness 



122 MECHANICAL DRAWING. 

of the walls of the box and the openings through the blocks, 
measuring the sizes carefully to the given dimensions. 

Draw the front elevation by projecting lines from the va- 
rious points on the end elevation, and assuming the position of 
the line AB measure off the lengths of the hor. lines and erect 
their vert, boundaries as shown by the figure. 

Prob. 37. — Given the end elevation of the last prob., cut 
by three planes A, B and C, Fig. 166. Draw the projections 
of these sections when the part to the left of the cutting plane 
has been removed, and what remains is viewed in the direction 
of the arrow, remembering that all the visual rays are parallel. 

These drawings and all that may follow are to be properly 
shade-lined in accordance with the principles given above. 

ISOMETRICAL DRAWING. 

In orthographic projection it is necessary to a correct 
understanding of an object to have at least two views, a front 
and end elevation, or an elevation and plan, and sometimes 
even three views are required. 

Isometric drawing on the other hand shows an object com- 
pletely with only one view. It is a very convenient system 
for the workshop. Davidson in his Projection calls it the 
" Perspective of the Workshop." It is more useful than per- 
spective for a working drawing, because, as its name implies 
('* equal measures ") it can be made to any scale and measured 
like an orthographic drawing. It is, however, mainly em- 
ployed to represent small objects, or large objects drawn to a 
small scale, whose main lines are at right angles to each other. 

The principles of isometrical drawing are founded on a 
cube resting on its lower front corner, i, Fig. 167, and its base 



OR THO G RA PHI C PR OJE C TION. 



125 



elevated so that its diagonal AB is parallel to the horizontal 
plane. Then if the cube is rotated on the corner i until the 
diagonal AB is at right angles to the vert, plane, i.e., 
through an angle of 90°, the front elevation will appear a& 
shown at i, 2, 3, 4, Fig. 167, a regular hexagon. 

Now we know that in a regular hexagon, as shown by Fig. 
167, the lines \A, ^3, etc., are all equal, and are easih' drawn 




Fig. T67. 

with the 30° X 60° triangle. But although these lines and 
faces appear to be equal, yet, being inclined to the plane of 
projection, they are shorter than they would actually be on 
the cube itself. However, since they all bear the same pro- 
portion to the original sizes, they can all be measured with 
the same scale. 

We will now describe the method of making an isomet- 
rical scale. 

Draw the half of a square with sides = 2h_" , Fig. 168. 
These two sides will make the angle of 45° with the horizontal. 
Now the sides of the corresponding isometrical square, we have 
seen, make the angle of 30° with the horizontal, so wc will 



124 



MEC HA NJCA L DKA WING. 



draw 14, 34, making angles of 30° with 1,3. The differ- 
ence then between the angle 2, i, 3 and the angle 4, i, 3 is 
15°, and the proportion of the isometrical projection to the 
actual object is as the length of the line 3, 2 to the line 3, 4. 
And if the line 3, 2 be divided into any number of equal parts, 
and lines be drawn through these divisions par. to 2, 4 to cut 
the line 3, 4 in corresponding divisions, these will divide 3, 4 
proportionately to 3, 2. 

Now if the divisions on 3, 2 be taken to represent feet 
and those on 3, 4 to represent 2 feet, then 3, 4 would be an 
isometrical scale of j-. 




Fig. 168. 



Since isometrical drawings may be made to any scale, we 
may make the isometrical lines of the object = their true size. 
This is a common practice and precludes the need of a special 
isometrical scale. 

The Direction of the Rays of Light. — The projection of a 
ray of light in isometrical drawing will make the angle of 30° 
with the horizontal as shown by the line 3, 2 on the front 
elevation of the hex., Fig. 167. And the shade lines will be 
applied as in ordinary projection. 

Prob. 38. — To make the isometrical drawing of a two- 
armed cross standing on a square pedestal. 



ORTHOGJ^APHIC FKOJECTION. 



12; 



Begin by drawing a center line AB^ Fig. 169, and from the 
point A draw AC and AD, making an angle of 30° with the 
horizontal. Measure from A on the center line AB a dis- 
tance — -f-^", and draw lines par. to AC, AD\ make AC and 
AD 2^' long and erect a perpendicular at D and C, complet- 
ing the two front sides of the base, etc. 




Fig, 169. 



PROB. 39. — To make the isometrical drawing of a hollow 
cube, with square block on each face and a square hole 
through each block, to dimensions given on Fig. 170. 

As before, first draw a center line, and make an isometrical 
drawing of a 2\" cube, and upon each face of it build the 
blocks with the square holes in them, exactly as shown in 
Fig. 170. 

PROH. 40. — To project an isometrical circle. 

The circle is enclosed in a square, as shown by Fig. 171. 



126 



ME CHA .\ V CA L DRA Wn\ 'G . 



Draw the circle with a radius = 2" and describe the square 
I, 2. 3, 4 about it. 

Draw the diagonals i, 2, 3, 4 and the diameters 5, 6, 7, 8 
at right angles to each other. 

Now from the points i and 2 draw lines lA, \B and 2A, 
2B, making angles of 30° with the hor. diagonal I, 2. And 



I 




Fig. 170. 

through the center O draw CD and EF at right angles to the 
isometrical square. 

The points CD. EF, and GH will be points in the curve 
of the projected isometrical circle, which will be an ellipse. 
The ellipse may be drawn suf^ciently accurate as follows: 
With center B and radius BC describe the arc CF and ex- 
tend it a little beyond the points C and F, and with center A. 
and same rad. describe a similar arc, then with a rad. which 



ORTHOGRAPHIC PROJECTION. 



12' 





Fig. 173. 



Fig. 175. 





Fig. 176. 



p'lG. 177. 



128 



MECHANICAL DRAWING, 




Fig. 178. 



Fig. 179. 




Fig. 180. 




Fig. 181. 




Fig. 182. 




Fig. 183. 



4 



ORTHOGRAPHIC PROJECTION. 1 29 

may readily be found by trial, draw arcs through the points G 
and H and tano^ent to the two arcs already described. 

Prob. 41. — To lay off an angle from a corner of the iso- 
metrical cube. 

Construct an orthographic square of any convenient size as 
shown in Fig. 174, and draw the required angle AOB. From 
the corner of the isometrical cube where the ande is to be drawn 
lay off along the side a distance equal to OA of the orthographic 
square and erect a perpendicular at A. Step off the distance 
AB and draw OB the angle required. Any other angle may be 
drawn in similar manner. 

Figs. 177, 178, 179, 180, 181, and 184 are for practice in 
the apphcation of the preceding principles, and at least one 




Fir.. T^4. 

of these should be drawn, or it would be better still if the student 
would attempt to make an isometrical projection of his instru- 
ment-box, desk, or any familiar object at hand. These figures 
may be measured with the lY' scale and drawn with the 2" 
scale. 

WORKING DRAWINGS. 

Working drawings are sometimes made on brown detail- 
paper in pencil, traced on tracing-paper or cloth, and then blue- 
printed. 

The latter process is accomplished as follows: 




130 MECHANICAL DRAWING 

The tracing is placed face down on the glass in the print- 
ing-frame, and the prepared paper is placed behind it, with the 
sensitized surface in contact with the back of the tracing. 

In printing from a negative the sensitized surface of the pre- 
pared paper is placed in contact with the film side of the 
negative, and the face is exposed to the light. 

The blue-print system is almost universal in its application 
to shop drawings, as evidenced in the report on " Conventions '* 
found at page 165. 

A Working Drawing in the hands of an experienced workman is 
intended to convey to him all the necessary information as to shape, 
size, material, finish, etc., of a machine or other object that will 
•enable him to properly construct it without any additional in- 
structions. This means that it must have a sufficient num- 
ber of elevations, sections, and plans to thoroughly explain 
and describe the object in every particular. And these views 
should be completely and conveniently dimensioned. The 
dimensions on the drawing must of course give the sizes to 
which the object is to be made, without reference to the scale 
to which it may be drawn. The title of a working drawing 
should be as brief as possible, and not very large — a neat, 
plain, free-hand printed letter is best for this purpose. 

Finished parts are usually indicated by the letter " f," and 
if it is all to be finished, then below the title it is customary 
to write or print '' finished all over." 

Working drawings may be divided into three general types, 
viz.: General Plans, Machine Drawings, and Patent Ofl&ce 
Drawings. 

General Plans consists of foundation drawings, piping draw- 
ings, layout drawings, maps, etc. 



ORTHOGRAPHIC PROJECTION. 



131 




132 



MECHANICAL DRAV/IXG. 




ORTHOGRAPHIC PROJECTION. 



m> 



Machine drawings include assembly drawings, detail draw- 
ings, diagram and kinematic drawings, sketches and scheming 
sheets. 

Patent Office drawings must conform to the requirements of 
the U. S. Patent Office as published in the "Official Rules of 
Practice." They are generally made on two sheet white bristol 
board with black ink. Size of sheet lo'^XiS^' with a one inch 
margin all around. From the top border line of one of the nar- 
row edges i\'' at least should be reserved for title, number and 
date. The signatures of inventor, attorney, and witnesses must 
be placed at the bottom of the sheet inside the border line. 

Figs. 185 and 186 are Assembly Detail drawings of two shaft 
couplings, fully dimensioned. 

Prob. 42. — Make detail drawing of the Butler's frictional 
shaft coupling shown in Fig. 185. Scale, full size. 

Prob. 43. Make drawings of a Stuart's coupling for if" 
shaft as shown in Fig. 186. Scale, full size. 

These couphngs are described in detail in ''Mechanical 
Drawing and Elementary Machine Design," by John S. 
and D. Reid, John Wiley & Sons, New York. 



I 



COURSE I. 
PROBLEMS IN MECHANICAL DRAWING 

INCLUDING 

LETTERING, GEOMETRICAL DRAWING, ORTHO- 
GRAPHIC PROJECTION, DEVELOPMENTS, IN- 
TERSECTIONS, ISOMETRICAL DRAWING AND 
WORKING DRAWING. 



COURSE I. 

MECHANICAL DRAWING. 

MINIMUM NUMBER OF PLATES AND MAXIMUM NUM- 
BER OF HOURS ALLOWED TO COMPLETE EACH 
DIVISION OF THE WORK. 

FIRST SEMESTER. 

Plates i to 6 inclusive, consisting of free-hand lettering must 
be completed and handed in on or before Friday, Oct. ic, 
1908. (26 hours.) 

All lettering on regular period will then stop and the 
work on Geometrical Drawing will begin. 
Plates 7 to 10 inclusive, must be completed and handed in on 
or before Wednesday, Nov. 25. (22 hours.) 

W^orks on Orthographic Drawing will begin on Monday, 
Nov. 30. 
Plates ii to 14 inclusive, must be completed and handed in on 
or before Friday, January 29, 1909. (28 hours.) 
Students failing to finish any of the divisions of the work 
within the time allowed, by reason of excused absence, may 
make arrangements with the instructor to work in one or more 
extra periods. 

137 



138 MECHANICAL DRAWING. 

Students doing more than the required number of plates 
in the given time will receive a higher mark, other things being 
equal. 

END OF FIRST SEMESTER. 



Note. — Registered freshmen conditioned in Mechanical Dravir- 
ing will be required to complete satisfactorily the following 
plates of this course: i to 6 inclusive, 10, 11, 12, 14, 17, 19, 
21, and 22, according to the directions given in the text. Con- 
ditioned students must work at least six hours per week. When 
the above plates are finished, work on Machine Drawing may 
be commenced. 



SECOND SEMESTER. 
Orthographic Projection continued, beginning Feb. 2, 1909. 

Plates 15 and 16 must be completed and handed in not later 
than Friday March 5, 1909. (18 hours.) 
March 8, work on Developments begins. 
Plates 17 and 18 must be finished and handed in not later 
than Friday, April 2, 1909. (16 hours.) 
April 5, work on Intersections begins. 
Plates 19 and 20 must be finished on or before Friday, April 
23, 1909. (12 hours.) 

April 26, work on Isometrical Drawing begins. 
Plate 21 must be completed by Friday, May 7, 1909. (8 hours.) 
May 10, work begins on the last required plate of the 
course consisting of a "Working Drawing." 
Plate 22 must be completed and handed in not later than Friday, 
May 21. (8 hours.) 
Students failing to complete any of the divisions of the course 
satisfactorily within the time allowed (for excusable reasons), 



PROBLEMS IN MECHANICAL DRAWING. 139 

may make arrangements with the Instructor to work in one or 
more extra periods. 

Students doing more than the required number of plates in 
the given time will receive a higher mark, other things being 
equal. 

enp of second semester. 

Directions to be Carefully Observed when Commencing 
Work in Mechanical Drawing. 

students' conduct in class. 

Students will be expected to give strict attention to their 
lettering or drawing work during the full time of each drawing 
period. Materials and instruments must not be put away until 
the warning bell rings. 

Nothing should be brought to the drawing table that is not 
needed for the drawing work in hand. 

If a student expects to be absent from any regular period 
he should endeavor to get excused by the Instructor and make 
arrangements for making uj) the work. 

A student coming late to class should report at once to the 
Instructor, otherwise he will be m.arked with an uncxcused 
absence. A report from the Instructor concerning the deport- 
ment of each student in class is expected by the Dean every two 
months. 

When a student is absent from class through an unforsccn 
cause he should at the next regular period fill out an absence 
blank, giving date and cause of absence, sign it, and hand to 
Instructor. The work of all absent periods must be made up 
by arrangement with the Instructor. 



140 



MECHANICAL DRAWING. 



Plate i. Freehand Lettering, Fig. 187, page 140. — Use the 4H 
pencil sharpened to a long conical point, not too sharp. 




"^ V J 



< 
P-i 








^ 



'oL^ 







\J 






Locate the lower point of the first guide-line 12 squares 
from top and 7 squares from left-hand edge of cross-section pad. 



PROBLEMS IN MECHANICAL DRAWING. 141 

Guide-lines should be sketched lightly with a downward 
stroke and allowed to remain until letters are approved. 



Q; ^ ^ .!5 5^-j|u^ 

^ ^ ^ H^^^H'^ 

^ h '^ ^ ^^^ j^^ ^ 

^ ^ I ^U.pSiM 

^ ^ "^J ^^lii^5!^^ 



•^ 






00 

00 



After drawing the guide-lines for llic curved letters, 
analyze the lines of each curved letter, as gi\en on the (//(/;■/ 
on the blackboard before attempting to (h-aw tlio curves 



142 MECHANICAL DRAWING. 

on the pad. A very close approximation of the first 
curved letter as it appears on the chart should be 
obtained before attempting to draw the second curved 
letter. 

Do not copy the letters or figures on pages 140 and 144, the 
correct form and proportions for all the letters and figures 
must be obtained by a careful study of the chart. 

The work on all the letters and figures must be strictly 
freehand. 

Place at the bottom of each plate at the right-hand corner 
the following information: Plate number, Section (days and 
hours), Time taken to finish plate, and Name, e.g., Mon. 
and Wed., 2-4, Plate 1. Time, 4 hours, Name. The 
height of these letters should be 07ie square high and all 
capitals 

Plate 2. Freehand guide lines must be drawn for all letters 
and figures higher than one square and allowed to remain 
until letters are approved. 

The same care as to proportion and form should be ob- 
sen^d in lettering this plate as in Plate i. 

Be careful to balance letters and numbers on all plates 
so that the same space will appear from both ends of line 
to edge of pad. 

The small letters should be extended in width a little be- 
yond the proportion given for the larger letters. 

The open letters should be spaced closely together and 
words should have a liberal space between them, say ij 
squares. 



PROBLEMS IN MECHANICAL DRAWING. 



M3 



Nl 



^ 

I 



[A 
H 
< 



1 



I 









5:^ 



V 



N 



It. 



.^ 











^ 



f^ 



^ 

^ 



nik: 






^ P ^ 



ir. ^ 



n 



(t 



so ::) 






N 



1 1 






1 



"< 



Is. 



I 

I 



^ 

^ 






I 






Nl 



11 



^ 

k 



3 






^ 






K: 



^ 
^ 









I 






I 

K 1(1 

% 

Ski 

^ k Or 
Ok, 



V: 

I 

I 



lOi 



* 



ti 



1^ 






00 



o 

•-4 



144 



MECHA NIC A L DRA WING. 



H 

< 







"0 



•Ifu 

Co 00 



O) ^^ 

r ^^ 

Ovi ^^ 



0| OQ >*» ^ 

ClJ ff) > V) 

^' (V) ^ ^ 

^ f^ >f "o 
C\l f^ ^J. ^ 
^ ") '^ 'O 

^4 f^ > ^ 

^ ^ \^ 'o 
C\j (V) \^ '<^ 

^ '^ \J. 'o 

^ fO V^ ^ 
^ fV) ^f ^ 
^ ^ V^ ^ 

'^J "D >ix ^ 

W eo ^ ^ 

^ y) ^^ 
^ ^ ^^ 

^ (i) ^f ^0 

^ (1) Vs ^ 

*^1 (t) > "o 

^' (^ ^ ^0 
euro ^^ to 

c\l H) ^^ ^ 

^ fO ^s 'O 
^ fO > ^ 
^ ^ ^^ 

^^ ^^ 
C\j (^ ^^ 

(\i (T) x^ V) 




<0 



*^ 

^^ 

^ cop) 
^ '^DO) 
^ ^C) 

^ Q) O) 

^ CO Q) 

^ q:) ^ 

(0 00 0) 
^ ^ 0) 

^ ^ C^ 
(0 CO c^ 
o <0 ^ 
(o<0 <i 



(1* 



PROBLEMS IN MECHANICAL DRAWING. 145 

Pencil three words only of the small letters at first and 
submit for criticism before going on with the others. 

Use Ball pen, No. 506, to ink large letters and No. 516 
for small letters and figures. 

Plates 3-6. — In the next three letter plates the directions for 
guide-lines, form, slope, spacing of letters, and for "cvidth of 
small letters should be carefully observed. 

Plate 6.* While a substantial majority of the leading 
drafting rooms in the United States are in favor of using Gothic 
Capitals exclusively for notes and titles, there are a number 
using a combination of Gothic Capitals and Lower Case letters. 
So it is deemed wise to introduce one plate of Lower Case letters 
to give the student some knowledge of their form, proportion, 
and construction. 

This plate should first be pencilled and after approval, inked. 
In addition to the ''Ball" pen. No. 516, for large letters, the 
small letters should be inked with Gillott's No. 303. All pens 
v/hcn new should be ''exercised" a little before beginning to 
letter. The form and proportion of these letters as given by 
the largest letters in Fig. 192, on page 147, should be adhered 
to as closely as possible. 

In general these letters should be made with down strokes 
of a uniform pressure. The only exceptions are the letters r 



* All letters and figures should have uniform slope. Letters and figures of 
one square high should have a full half s([uarc slope. 

Each plate must be signed by Instructor in charge, in jiencil before inkin;; an.l 
in ink when plate is finished. TMates not so signed will be rejected. 

When plates are fmished and signed they will be retained by the student until 
the six plates on lettering are completed, when they are to be bound with pauL-c 
binders and handed to the Instructor. 



^4^ MECHANICAL DRAWING. 

^ )} ^^ t^ (t)(b ^^ Cj,^^ 

^ ^'l ^^ >4 %^ v^ ^l 

K ^"^ ^^ 1^^ %^ (oS q)cs» 

^ Vtj 0,0) ^f.^ (t)(b ^"o 0)0) 

^ 1^1- (DdJ 'ob KK ^ 

^ ^V ^CO ^^ KK ^^^ II 

^ :" r :!^ ^^ h 

o '* ^^ ,\^ ^^ n %^ 

1 1^ 'b.Q). S^ i^K ^[•>f (() oij 



Q) .^^ ^t ^' ^^ ^^ ^^ 

-^ "^^ \^ ^^ (^C^ ^«) KK 

")") KK f\ic\i 0,0^ ^^ Kk 



(^ "i'O KK «\ftVl 0)0) r.)!.) KK 

^ ^^ ^^' II II ^^ ^^ 

^ ^^ ^v^' ^' S; ^^^ ^-^ 

C\{ ^% %^. ");«). (C(jj ^^ (0^. 

> ^^ %^ •^0) lOH) ^C\l <5 (5) 

^ ^«Vl 'OiO ")!«) (t)(^) ^(^ ^(g) 



PROBLEMS IN MECHANICAL DRAWING. 



147 




•^^.^^-^-r 






■RJ 



N 






IS 






■^ 
^ 



to 






10 

vo 

I- 
5 



>-r 






I 



1 



1 

I 



1 
1 

■I 

1 



I 






o 

l-H 

1^ 



V 



148 MECHANICAL DRAWING. 

and w. The curved part of the r imay be made with an up stroke 
curved only at the top. The u is made with two down strokes 

I • 

^ ^ , ? ^ ^^ ^ ^ 



^ 



r^ 's 






ly 









Sx 



'K X ^ ^ R X C\i'^ro X{; ^^ ,i^ K 

and the bottom curve filled in with a stroke to the right and upward. 
The m, n, and h should be formed with nearly sharp upper curves. 



PROBLEMS IN MECHANICAL DRAWING. 149 

This plate will have to be repeated until the desired results 
have been obtained. 

Plate 6A, Fig. 193. This is an extra lettering plate for those 
students v^ho may finish the required plates ahead of time. The 
extra plate will increase the grade mark. 



GEOMETRICAL DRAWING, INCLUDING CONIC SEC 
TIONS; ORTHOGRAPHIC PROJECTIONS; DEVELOP^ 
MENTS; INTERSECTIONS; ISOMETRICAL DRAWING, 
AND ONE WORKING DRAWING. 

Before beginning the work in Mechanical Drawing read 
carefully the directions given on pages i to 17. The size of 
the sheet of cream drawing paper will be i5''X2o''. This size 
will be used for all drawings in mechanical and machine draw- 
ing. The border lines and inside divisions will be as shown 
on page 150, except where otherwise directed. 

Use a 6 H pencil sharpened to a long Vv^edge-shaped point, as 
explained on pages 7 and 8. 

The lead in the compasses must also be 6 H and sharpened 
in the same way. A properly sharpened pencil is necessary 
to obtain good work. 

When the work has been completely pencilled with fine sharp 
lines it should be submitted to the Instructor for approval and 
signature, after whicn the given and required lines of the ])roblem 
are to be repencilled with a strong, bold line, using a 4 H pencil 
sharpened to a conical point (not too sharp). 

Title. The form of title shown in Fig. 194 will be used 
on all drawings and should be pencilled and inked together wiili 
the border lines whethe-r the drawinji is to be inked or not. All 



150 



UECHA NIC A L DRA TT7 NG 



drawings are to be finished pencil drawings, as directed above, 
except where otherwise stated. 




Following is a list of the problems to be drawn on each 
plate : 



PROBLEMS IN MECHANICAL DRAWING, I5L 

Plate 7. (Pages 17 to 26 inclusive.) 

Problems i, 2, 3, 5, 6, 7, 9, 11, 13, 14, 15, 16, 18, 19, and 
20. Make the dimensions for each problem to suit the given 
space so as to comfortably fill it without crowding. 

Plate 8. (Pages 26 to 35.) 

Problems 21, 22, 24, 25, 26, 29, 30, 34, 35, 37, 39, 40, 41, 
42, and 44. 

Plate 9. (Pages 43 to 53.) 

Problems 54, 56, 57, 58, 59. Use four spaces for problem 
59: 70, 71 in one space, 72 and 73 in one space, and 63 in two 
spaces. 

Plate 10. (Pages 39 to 43.) 

Conic Sections. Divide the plate into nine equal spaces. 
Draw problems 47 and 48 (in problem 48 draw complete upper 
half of ellipse and draw lower half by "Honey's method," prob- 
lem 46), 49, 50, 51, 52, 53, and 55. Make twice the size given 
in the figures. 

Plate ii. (Study pages 74 to 89.) 

Orthographic Projection. Divide sheet into nine equal 
spaces, as shown in Fig. 195, page 152. 

Problem i shows three views of a wedge-shaped solid, viz., 
the vertical, horizontal, and profile projections. The vertical 
projection is commonly termed the "Elevation" or "Front 
Elevation;" the horizontal projection is generally called tlio 
"plan," and the profile projection is known as the "End 
Elevation" or "End View." 



i=;2 



MECHANICAL DRAWING. 



It will be seen that the end view is obtained by revolving 
points projected from the plan to the profile plane through an 




angle of 90° by means of arcs of circles and dropping perpendicu- 
lars to intersect horizontals from the same points in the elevation. 



PROBLEMS IN MECHANICAL DRAWING. 



153 



Problem 2. This is the same solid placed differently and 
having the end view projected by straight lines instead of by 
arcs of circles. This method will be adhered to in preference 
to the other, as it takes less time. 

Problem 3. Given the front and end sections of a rec- 
tangular pyramid ij'' wideXi'' thickX2" high. From the given 
views draw the plan. 

Problem 4. Given the plan of a pentagonal pyramid whose 
side is i'\ project the front and end elevations. 

Problem 5. Given the plan of an H-shaped block 2'' high, 
draw front and end elevations. 

Problem 6. Given the elevations of a + -shaped block, 
draw the plan. 

Problem 7. Given front elevation and plan of a hollow 
rectangular prism, draw the end elevation. 

Problem 8. Given the front eleyation of an L-shaped block 
2" long, draw the end elevation and plan. In the title of this 
sheet leave out the word "Details" and make title name "Ortho- 
graphic Projection." 

Plate 12. 

Problem i. Given the elevation and plan of a i\'' square 
pyramid i\" high, draw the end view. 

Problem 2. Given the same pyramid of problem i when the 
plan has been rotated to the left through an angle of 15°. Pro- 
ject the front and end elevations. 

Problem 3. Given the front elevation of the figure obtained 
in problem 2 when revolved to the left through an angle of 
15°. Draw the plan and end elevation. 

Problem 4. Given the front elevation of problem i when 



154 



MECHA NICAL DRA WING. 



revolved through an angle of 30° to the right. Draw the plan 
and end view. 

Problem 5. Given the end elevation of the pyramid ob- 
tained in problem 2 when revolved to the right through an angle 
of 15°. Project the front elevation and plan. 

PLATE 12. 





\n — Li^; 






1& 





"1 






Fig. 196. 



Problem 6. Given the end view of the pyramid obtained in 
problem 3 when revolved to the left through an angle of 45°, 
Draw the front elevation and plan. 

Problem 7. Given the end view of the pyramid obtained in 
problem 4 when revolved through an angle of 30° to the left. 
Draw the elevation and plan. 



4 



PROBLEMS IN MECHANICAL DRAWING. 



o:) 



Problem 8. Given the front elevation obtained in problem 5 
when revolved 30° to the right. Draw plan and end view. 
Title similar to that on Plate 10. 

Plate 13. 

In the same positions as given above draw the projections 
of a rectangular prism, Fig. 201, iY'Xi"X2'' high. 




Fig. 197. 





K-/*- 



V^ 



:^oi 





Fig. 199. 



^^tv<t 



Fig. 202. 







Fig. 205. Fig. 206. Fig. 207. 

Plate 14. 

Using same positions as in Plate 12, draw the projections of 
a hexagonal pyramid, Fig. 199, circumscribed circle of hexagon 
= i|'' diameter, height ij". 



156 MECHANICAL DRAWIXG. 

Plate 15. 

Given a pentagonal pyramid, Fig. 200^ whose side is i}'', 
height if", draw the projections of the various positions as 
required in Plate 12. 

Plate 15 5. 

In the same positions as given above draw the projections 
of a triangular prism, Fig. 202, page 155, side of triangle ij'', 
height of prism lY'- 

Plate 15 C 

In the same positions as given above draw the projections 
of a T-shaped block, Fig. 203, page 155. 

Plate 15 i^. 

In the same positions as given above draw the projections of 
a wedge. Fig. 204, page, 155. Plates 1$ B, 15 C, 15 D are extra 
plates to be drawn by those who finish the required plates ahead 
of time. 

Plate 16. 

Problem i. Given the elevation and plan of a hollow tri- 
angular prism in the position shown in Fig. 205, page 155. Com- 
plete the projection in the auxiliary plane. 

Problem 2. Given the elevation and end view of a hexa- 
gonal pyramid, draw the projection on the auxiliary plane, shown 
in Fig. 206, page 155. Use same dimensions given in Fig. 199. 

Problem 3. Given the elevation and plan of a wedge, draw 
the projection on the auxiliar}' plane, shown in Fig. 207, page 155. 
Use same dimensions given in Fig. 204. 



PROBLEMS IN MECHANICAL DRAWING. 



0/ 



Problem 4. Given elevation, plan, and revolved position 
of plan of a right circular cone. Fig. 214, page 157. Base 3'' 
diameter, height 3". Draw elevation and end view in revolved 
position. - See page 88. In planning position of drawings on 




Fig. 208. 



Fig. 209. Fig. 210. Fig. 211. Fig. 212. Fig 213. 




Fig. 214 



this plate, locate problems i, 2, and 3 along the top of the sheet 
and problem 4 in the lower left hand. 



Plate 17. Developments. 

Scheme the layout of all the problems in this plate before 
beginning to draw. 



158 MECHANICAL DRAWING. 

Problem i. Given the elevation and plan of a pentagonal 
prism, Fig. 208, page 157, 1" side, il" high, cutting planes A 
and B, draw projections as shown in Fig. 125, page 90. Draw 
the development of the part below the cutting plane B. See 
Fig. 126, page 90. 

Problem 2. Given elevation and plan of a rectangular pyra- 
mid, Fig. 209, page 157, 2"X^"Xii" high, and cutting planes A 
and B. Draw^ projections and development as required for 
problem i. 

Problem 3. Given views and cutting planes of equilateral 
triangular prism shown in Fig. 210, page 157. Draw sections 
and development. 

Problem 4. Given views and cutting planes of pyramid 
shown in Fig. 211, page 157. Draw sections and develop- 
ment. 

In this problem when laying out the development, allowance 
must be made for the unequal inclined edges of the sides of the 
pyramid. See Fig. 117, page 82. 

Plate 18. 

Problem i. Given the right circular cone, as shown in Fig. 
212, page 157. Draw sectional plan and development. 

Problem 2. Given pentagonal pyramid, Fig. 213, page 157, 
and cutting planes A and B. Draw sections and development. 

Problem 3. Given projections of right circular cone, Fig. 215, 
page 157, and cutting planes A, B, C, and D. Draw the pro- 
jections of conic sections as indicated by center lines. Draw 
also development of part of cone below cutting plane B. If 
space will not permit of full development draw half. See Fig. 130, 
page 95. 



PROBLEMS IN MECHANICAL DRAWING. 



I5Q 



Plate 19. Intersections. 

Problem i. Draw three views of two right circular cylinders 
of equal diameter, shown in Fig. 216, page 159, intersecting at 
right angles to each other. Draw curve of intersection. See 
page 96. 

Fig. 216. Fig. 217. 




Fig. 218. Fig. 219. 

Problem 2. Make the drawing shown in Fig. 217, page 159, 
and draw curve of intersection. 

Problem 3. Make drawing shown in Fig. 218, page 159, 
and project curve of intersection. 

Problem 4. Fig. 219, page 159, shows a square prism inter- 
sected by a hexagonal prism partly shown in elevation. Com- 



l6o MECHANICAL DRAWING. 

plete the elevation and draw also half end view. Total length 
of hexagonal prism 4I''. 

Plate 20. 

Problems i and 2. Construct the curves of intersection 
shown on the connecting-rod ends in Figs. 140 and 141, page 102, 
and draw three complete views of each. 

Problems 3 and 4. Draw the projections of a "V" and 
** Square" threaded screw according to directions given on pages 
99 and 100, Figs. 137 and 138. 

Plate 21. Isometrical Drawing. 

See pages 122 and 123. 

Problem i. Make the isometrical drawing of a 2f cube. 
Draw a 2^'' isometric circle on the upper face by the method 
shown in Fig. 171, page 127. From the lower left-hand corner 
of the right-hand face lay off angles of 15°, 30°, and 45°. Use 
method shown in Fig. 174, page 127. See problem 41, page 129. 

Problem 2. Draw the hollow cube as shown in Fig. 170, 
page 126, except that instead of the hollow block on the upper 
face draw a cylindrical prism of if diameter and i'' high. 

Problem 3. Make the isometrical drawing of a hexagonal 
headed bolt, shank i^' diameter and 2'' long. Head i'' thick. 
Use either of the methods shown in Figs. 173 and 175, page 127. 

Problem 4. Make the isometrical drawing of a pentagonal 
prism of i|'' sides and 2^^ high. On the top of the prism draw 
an isometric circle of 2'' diameter. See Fig. 176, page 127. 

Problem 5. Make the isometrical drawing of the tool box 
shown at Fig. 183, page 128. Dimensions 3^' long X 2'' wideX i" 
deep, over all. Cover and sides Y' thick. Use the method of 



i 



PROBLEMS IN MECHANICAL DRAWING, 



l6l 



offsets shown in Fig. 182, page 128. Place full dimensions on 
this drawing. Plate 21 is to be finished in pencil and inked. 
See directions for inking with the spring bows on page 14, the 



PLATE 22. 



0/A-t£/VS/OA/S //V rB£T MM/=t^ rH L/S ^T //V //\/CMES A4/^/^/< TZ-fUS £?/ MS/^S/O/VS OF CB'SS 7>t>J/V 

TiVO /^££r ^ff£ TO 3£ G/i^£^f /fsj /NCH£S ^/?/?Ot/' /-f£y>DS THUS - A/OT TMUS > 

fiiy^D// /ND/CATEO By /? COMP^ere O/M£/\/S/0f^S 










Fig. 220. 



large compass on page 13, and the ruling pen on page 9. See 
also directions given for inking Plate 22 on page 161. 



Plate 22. Working Drawing. 

Problems i and 2. Make the working drawing of connecting 
rod and axle shown in Fig. 220, ])age 161. Begin by laying off 
the border line and s[)ace for title. Draw guide-lines \" high 
and \" space between lines. Locate all center lines of rod and 



l62 



MECHANICAL DRAV/IXG. 



axle. Use 6 H pencil sharpened as directed on page 8. Draw 
fine, clear, clean-cut lines. \Mien drawings of rod and axle 



^ 



















IS; P 

5 s m 

IS I 

g ^ 5 

<>. t 15 

f ^ S: 



r-„H§fc 





k-p- 



-^/■» 






are complete and approved, strengthen the lines with 4 H pencil, 
conical point. Then draw dimension lines. Next put in arrow- 



PROBLEMS IN MECHANICAL DRAWING. l6j 

heads and dimensions, beginning at the upper left hand and 
working down toward the lower right-hand corner. 

When the drawing is properly finished in pencil and signed 
by the Instructor it will be ready for tracing on cloth. Begin 
the tracing with the spring bow pen. Ink all arcs of circles, 
circles, and irregular curves before inking any straight lines. 
Then ink dimension lines. Next ink arrow-heads and dimen- 
sions in consecutive order, beginning with the left-hand arrow- 
head, then dimension, next sign of inches, and then left-hand 
arrow-head. Ink hatch lines and center lines last of all. For 
weight and character of hnes see "Conventions" on page 165. 

Plate 22 F. 

Problem i. Make drawing of automobile crank axle, as 
shown in Fig. 221, page 162. Use same directions for pencilling 
and inking as given for Plate 22. 

Problem 2. Make drawing of top bracket for planing ma- 
chine, as shown in Fig. 221, page 162. 'Project also right end 
view of bracket. Make finish pencil drawing and trace on cloth. 

This plate is not required in the course of mechanical draw- 
ing, but credit will be given for it in the Freshman Course to those 
who may have time to finish it in this course. A higher mark 
will be given to the student completing this plate in addition to 
the required plates. 



Course I is preparatory to Courses II and III in Machine 
Drawing and Design. 

Courses II and III arc given in '' Mechanical Drawing 
AND Elementary Machine Design," by John S. and D. Rcid, 
John Wiley & Sons, New York. 



4 



PRESENT PRACTICE IN DRAFTING ROOM 
CONVENTIONS AND :\IETHODS IN MAKING 
PRACTICAL WORKING DRAWINGS. 



Summary Report of an Investigation made by the Writer 
WITH the Authority of the Armour Institute of 
Technology, Chicago, III., into the Present Prac- 
tice OF THE LEADING DRAFTSMEN IN THE UNITED STATES, 

in the USE OF Standard Conventions and Methods 

WHEN MAKING COMMERCIAL WORKING DRAWINGS. 

A circular letter accompanied by a list of thirty-five questions 
was submitted to two hundred leading firms in the United States 
embracing nearly all kinds of engineering practice. 

The returns have been exceedingly gratifying, and especially 
so has been the spirit with which the ''Questions" have been 
received and answered. 

Many requests have been received from chief draftsmen for 
a copy of the returns. 

The questions submitted and the answers received are given 

somewhat in detail below. 

i6s 



l66 MECHANICAL DRAWING. 

Q. I. Do you place complete information for the shop on the 

pencil drawing, such as all dimensions, notes, title, bill of 
material, scale, etc.? 

Complete information is placed on drawing before tracing. 57 

Complete information is placed on tracing only 42 

Principal dimensions and title only on pencil drawing 2 

Draw directly on bond paper 10 

Did not answer this question 10 

Sometimes 7 

Reasons given for making the pencil drawing complete: 

To arrange notes. To save ime. The tracing is not usually 
made by the draftsman who makes the pencil drawing. 

Q. 2. Do you ever ink the pencil draAving? 

Never ink the pencil drawing 91 

Generally ink the 'pencil drawing 7 

Sometimes ink the pencil drawing 8 

Sometimes ink the pencil drawing and shellac it for shop use. i 

Use bond paper 10 

Make pencil drawings on dull side of tracing cloth 2 

Ink center lines of assembly drawing i 

Ink center lines of pencil drawings in red 2 

Q. 3. Do you trace on cloth and blue print? 

Always trace on cloth and blue print 102 

Blue print from bond paper 10 

Blue print from bond paper occasionally i 

Sometimes make "Vandyke " prints for shop use i 

Sometimes use paper drawings in shop for jigs and fixtures. i 

Q. 4. Do you use blue prints entirely in the shop ? 

Use blue prints altogether in shop 105 

Sometimes use pencil drawings or sketch 21 



PRESENT PRACTICE IN DRAFTING ROOM CONVENTIONS. 167 

Sometimes use sketches made with copying ink i 

Sometimes use prints from " Vandyke " i 

Use white prints mounted on cardboard and varnished i 

Use blue prints mounted on cardboard i 

Use sketches for rush work i 

Q. 5. When tracing do you use uniform wide object lines? 
Ever use shade lines ? 

Use uniform, thick object lines. Never use shade Hnes 100 

Sometimes use shade lines 21 

Use shade lines on small details 5 

Always use shade lines 14 

Experts in the use of shade lines may do so to make drawings 

clear i 

Shade rounded parts i 

Q. 6. What kind of a center line do you use ? 

Long dash, very narrow, and dot, thus: 42 

Long dash and two dots, 29 

Very fine continuous line, 19 

Very fine dash line, long dashes, 8 

Long dash and dot in red, 3 

Continuous fine red line, 8 

Long dash and three dots, i 

Long dash and two dots, thus: | | 1 

Q. 7. What kind of dimension line do you use? 

Continuous fine line, broken only for dimension 52 

Fine long dash line, 32 

Fine long dash line and dot, 13 

Fine continuous red line, 8 

F'ne continuous blue line, 4 

Fine continuous green line, 1 



1 68 MECHANICAL DRAWING. 

Same character of line as center line, 2 

Dotted line, - I 

Long dash and two dots, ■ 2 

Heavy broken lines, i 

Q. 8. What style of lettering do you use? Sloping? Vertical? 
Free-hand? K\\ capitals of uniform height? or capitals 
and lower case ? 

Free-hand sloping 52 

Free-hand vertical 45 

Free-hand capitals, Gothic, uniform height 61 

Free-hand capitals, and lower case 40 

All caps, initials shghtly higher 5 

Lettering left to option of draftsman . . . , 2 

Mechanical lettering, all caps 3 

Not particular, the neatest the draftsman can make free- 
hand . . , 4 

Mechanical lettering, all caps, sloping 2 

Give great latitude in lettering, only insist it be bold and neat i 

Roman, caps and lower case, free hand 2 

Large letters Aths, small ^\ds and Jth 2 

•Q. 9. Are your titles and bills of material printed or lettered by 
hand ? 

Lettered by hand 79 

Standard titles printed and filled in by hand 12 

Bill of material table printed and lettered by hand 12 

Lettered by hand, contemplate having them printed i 

B. of M. typewritten on separate sheet and blue printed 8 

Titles partly printed and filled in by hand 8 

Use rubber stamp for standard title, fill in by hand 6 

Standard title, bill of material lithographed on tracing 

cl@tn 8 



3 



FRESEXT PRACTICE IX DRAFTIXG ROOM COXVEXTIOXS. 169 

Q. 10. Do you use a border line on drawings? 

Always use border lines gy 

Never use border lines 13 

Use border lines on foundation plans, to send out i 

No border lines on detail drawings i 

Intend to discontinue the use of border lines i 

Border lines used only on design drawings i 

Only on drawings to be mounted on cardboard i 

Only used for trimming blue print 2 

On assembly drawings only i 

Width of margins reported: i", \", |", \", and \'\ 

Q. II. When hatch-lining sections, do you use uniform or 
symbolic hatch lines? 

Standard symbolic lines 59 

Uniform hatch lines for all materials . 44 

Shade section part with 4H pencil and note name of material 4 

Symbolic hatch lines and add name of material 3 

Uniform hatch lines for metal only i 

Uniform on details, symbolic on assembly drawings 5 

Pencil hatch on tracings and note material other than cast 

iron I 

Uniform hatch lines, sometimes solid shading i 

No uniform system i 

Sections tinted with water colors representing the metals.. i 

Q. 12. Is the pencil drawing preserved? Is the tracing 
stored or do you make "Vandyke" prints for storing away? 

Store tracings only 96 

Pencil drawings preserved for a time 30 

Pencil drawings preserved 13 

White prints made and bound for reference i 

Tracings kept in office for reference, blue prints stored 9 

" Vandyke " prints stored i 



lyo MECHANICAL DRAWING. 

Use " Vandyke "as substitute for tracing 2 

Arrangement drawings preserved, detail drawings destroyed 
after job is completed. Pencil drawings used for gasket 

paper , . . i 

Original pencil drawing inked and stored i 

Assembly drawings and layouts preserved 4 

Patent office drawings preserved. i 

Tried " Vandyke " but found it unserviceable, tearing easily. i 

Q. 13. Do you use 6H grade of pencil for pencil drawings or 
w' hat ? 

6H 73 

4H, mostly for figures and letters 52 

5H 16 

Ranging from 2H to 8H 53 

Q. 14. Do you use plain orthographic projection for free-hand 
sketches? Ever use perspective or isometrical drawing for 
sketches ? 

Plane orthographic 3d angle projection 99 

Isometrical drawing for sketches 25 

Perspective for sketches i 

Isometric for piping layouts and similar work 8 

Perspective and isometric for catalogue work 2 

Isometric sometimes 6 

Never use free-hand sketches 6 

One says, "When we run into other than orthographic, men are 
too timid and not sure of themselves. In perspective drawings when 
work is cylindrical, workmen get mixed up on center lines. 

Q. 15. What sizes of sheets do you use for drawings? 

9" X 12'' 13 

12" X 18'' 16 




1 



PRESENT PRACTICE IN DRAFTING ROOM CONVENTIONS. 171 

18" X 24" . . 20 

24'' X 36" 19 

There seems to be little uniformity in the sizes of shop drawings, 
about 67 firms reporting different combinations. A few have no 
system but simply make the size of sheet to suit the object to ];e 
drawn. 

Q. 16. Do you use red ink on tracings? 

Never use red ink on tracings 57 

Recently discarded the use of red ink 2 

Use red ink for pattern figures i 

Use red ink for center and dimension lines 8 

Use red ink for check marks i 

Use red ink for existing work on studies i 

Use red ink sometimes 2 

Use red ink on occasions when it is desired to show old work 

in red and new work in black (use carmine) i 

Use carmine for brick i 

Qs. 17 and 27. How indicate finished surfaces on drawings? 
When finished all over? When ''file finished," ground, 
planed, bored, drilled, etc. ? 

Finished surfaces indicated as in Fig. i 65 

Finished surfaces indicated as in Fig. 2 16 

Finished surfaces indicated as in Fig. 3 8 

Finished surfaces indicated as in Fig. 4 2 

Finished surfaces indicated as in Fig. 5 2 

Bound the surfaces with red lines 2 

Bound the surfaces with dotted Hncs 2 

Name the finish b}- note in full 63 

Do not specify machinery method 6 

(See drawing.) 



172 



MECHA NIC A L DRA WING. 



Q. 18. Do you use horizontal or sloping lines for convention 
in screw threads? 

Sloping lines, see Fig. 6 94 

Horizontal lines, see Fig. 7 12 



/=/G. /. 
f/G. ^. I 



FJG.6. 





/F 



■^ 



/=/A/. 



Finish only third line from top 

— U LJ~ 



^U. 




Fig. 6. 



Fig. 7. 



^^ 



Fig. 8. 



I 



:y 



n 



Fig. 9. 



i^. 



Fig. 10. 



Horizontal lines, see Fig. 8 13 

Both 7 

Neither, but as shown in Fig. 9 i 

Neither, but as shown in Fig. 10 i 



PRESENT PRACTICE IN DRAFTING ROOM CONVENTIONS 173 

Q. 19. \\nien a large surface is in section do you hatch-line 
around the edges only? 

Hatch-line edges only 62 

Sometimes 3 

Hatch section all over 54 

Do not use hatch lines; shade the whole surface with 4H 

pencil 3 

Usually show a broken surface line i 




Q. 20. Do you section keyways in hubs or show by invisible 
lines ? 

Section keyways as shown in Fig. 11 73 

Show key way by invisible lines, see Fig. 12 40 

Keyways in hubs left blank i 

Q. 21. In dimensioning do you prefer to place the dimension 
upon the piece or outside of it ? 

Outside whenever possible 02 

Upon the piece 13 



174 MECHANICAL DRAWING. 

Both, according to size and shape of part 19 

No rule i 

Commenting on placing dimensions outside of piece one says, 
"It entails less confusion to workman." Another says: "So as to 
make detail stand out." 



Q. 22. Do you use feet and inches over 24 inches? 

Yes 69 

Use feet and inches over 36'' 4 

Use feet and inches over 24'^ on foundations and outlines . . 2 

Use feet and inches over 48'' 6 

All inches 21 

For pulleys use inches up to 48" i 

Inches up to 10 feet 2 

Start feet at 24'' thus : 2—0" 2 

Usually, but not always 2 

Yes, except pitch diameters of gears, which are all given in 

inches 2 

Yes, except in boiler and sheet iron work 3 

Use feet and inches over 12'' 6 

Inches up to 100" 3 

Inches up to 60" i 

Q. 23. How do you indicate feet and inches? Thus 2 ft. 4", 
or thus 2—4"? 

2-4''— 97, 2^^ 4^—5, 2 FT. 4"— 2, 2ft. 4"— 13. Both 2ft. 4'' 
and 2-4" — I, 2rT. 4 in. — i, 2' 4'' — 8, 2-4^ — i. 

Q. 24. Do you dimension the same part on more than one view ? 

One view 94 

More than one view as check 46 



I 



PRESEXT PRACTICE IX DRAFT I XG ROOM COXVEXTIOXS. 175 

Q. 25. When several parts of a drawing are identical would the 
dimensioning of one part sufhce for all, or would you repeat 
the dimension on each part ? 

One part only 82 

Would repeat or indicate by note 39 

*' Left to judgment of draftsman " i 

"When ic is evident that several parts are identical the dimensioning 
of one part would suffice, 'Would never leave room for doubt.'" 

Q. 26. Do you write R for radius or rad. ? D. for diameter 

or DIA. ? 

RAD . . 35 Rad . . .47 R .... 32 rad. . . i r 3 

DIA . . 41 Dia . . 48 D. ... 15 d . . . . 3 dia . .. 4 
DiAM .... I Diam. 3 diam 5 

Do not use R. or rad., dimension only i 

Q. 28. Do you always give number of threads per inch? 
When you do how are they indicated ? 
Only give number of threads when not standard 67 

All others always indicate number of threads in a great variety of 
ways. A few of the different styles of noting the threads are given 
below: 

I" — 10 Thr. 5THDS. PER i'\ 8thds. 4 threads per inch. Mach. 
Screw 10-24, li" XII, 16 P. RH. Vth. U. S. S. XVIII, i''-8- 

U. S. S. l'' TAP, 8 PITCH, 3 TH'd R. H. SQ. DOUBLE, 5''-l8 

THDS. R. II. OWN st'd io thds. per inch. For pipe tap thus 
J" P.T., etc., etc. 

Q. 29. How do you ''Mark" a piece to indicate on the bill of 
material? 

Number it on drawing and put a circle around it 34 



176 MECHANICAL DFLAWIXG. 

By name or letter 35 

By pattern number 2 

By symbol and number v 14 

Castings, I, II, III, Forgings, i, 2, 3. 

Q. 30. When a working drawing is fully dimensioned why 
should the scale be placed on the drawing ? 

For convenience of drafting room 25 

Check against errors 11 

Not necessary 18 

Scale not placed on shop drawings 18 

For convenience in calculations and planimeter work i 

To give an idea of over-all dimensions when these are not 
given. "We never saw a drawing so fully dimensioned 

as to warrant leaving off the scale " 2 



I 



'O 



" If a drawing is to scale the scale should be on the drawing, whether 
it is needed or not." 

" It gives every one interested a better conception of the proportions 
of the piece, and there are frequently portions of a design which do 
not require a dimension for the shop to work to, and which it is 
interesting to scale from an engineering point of view." 

"To get approximate dimensions not given on drawing." 

"Impractical to dimension all measurements for all classes of 
work." 

"Scale will tell at a glance, dimensions would have to be 
scaled." 

"To obtain an idea of relative size of parts without scaling the 
drawings." 

"To sketch on clearance." "To proportion changes." "\Mien 
erecting to measure over-all sizes." 

" In case a dimension has been left off, the scale will help out." 

" This is a question of opinion ; some will not have the scale, others 
insist on it." "We always give the scale." 



PRESENT PRACTICE IN DRAFTING ROOM CONVENTIONS. 



^17 



"It is an immense help and time saver in the drawing room.'' 

" Generally no reason. In our work we combine standard apparatus 
by 'fudge' tracing, and it is convenient to know scale so all parts will 
surely be to same scale." 

" In discussing alterations, additions, clearances, etc., it is con- 
venient to know the scale instantly." 

"For convenience in drafting room. We often put an arbitnirv 
scale on with a reference letter indicating scale to draftsman." 

"To give toolmaker an idea of the size of the finished piece." 

"As an aid to the eye in reading." 
Above are some of the reasons given for placing the scale on the 

drawing. Below are given a few of the reasons why some do not 

place the scale m the dnwina;. 

*' Scale should never be used in shop," says one. 

"Not necessary. Sometimes drawing is made out of scale." 

"Not advisable, on account of workmen ^^i^iiing into the habit of 
working to scale instead of to the figures." 

" Know of no good reason at all." 

"Believe it best to leave scale off." 

" Should not. Drawing should never be scaled.'* 

"Know of no good reason why it should be." 

"Should not be given on drawing." 

"Do not object if left off, not needed." 

Q. 31. Do you use the glazed or dull side of tracing cloth? 
Dull side... 66 Glazed side. 32 Both 4 

"Dull side, because it lies flat better in drawers." 

"Dull side, so that changes which may be necessary while work is 
under construction, can be made easily in pencil and later in ink." 

"Dull side so tracings may be checked in pencil." 

"It prevents curling." 

"Both, although the glazed side when traced on lies better in the 
drawer." 



178 MECHANICAL DRAWING. 

"We wse cloth glazed on both sides, work on convex side, so that 
shrinkage of ink will eliminate camber." 

"Dull, except for U. S. Government, who requires the glazed side 
to be used." 

Q. 32. How do you place pattern numbers on castings? 

Pattern number with symbol or letter is placed on or near 
the piece, e.g., PATT.-D-478-C 36 

This question was not happily stated: most answers gave "raised 
letters cast on," w^hile the question like all the others refers to the 
marking of the drawing. 

Q. 33. How do you note changes on a drawing? 

On tracing with date 32 

New tracing and new number 17 

Put a circle around old figure and write new figure beside 

it with date 8 

Make new tracing = 5 

Red ink with date 8 

Use rubberstamp " Revised" with date^ and indicate changes 

on record print 28 

Use change card system i 

Special forms for purpose. Change made in a book with 
date. New prints made to replace. In place at title 

with draftsman's initials and date 8 

Q. 34. Do you place dimensions to read from bottom and 
right hand, or all to read from bottom, or how ? 

Bottom and right hand ... 103 From bottom only 2 

No fixed rule 2 

Prom R to L and bottom to top i 



i 



PRESENT PRACTICE IN DRAFTING ROOM CONVENTIONS. lyg 

Q, 35. Do you always make a table to contain the bill of 
material ? 

Yes. . 49 No 25 Not always. . 5 

Usually I Use separate bill 32 

Bills on general drawings only. On details number is marked on 
piece. 

"No, but it is advisable to do so." "Have abandoned that 
system." 



^ 



INDEX. 



A 

PAGE 

Angle, To bisect an 19 

Angle, To construct an 15 

Anti-friction curve, " Schiele's " 50 

Arched window-opening, To draw an 53 

Arkansas oil-stones 5 



B 

Baluster, To draw a 53 

Board, Drawing , i 

Bow instruments 2 

Brass, Sheet of 6 

Breaks, Conventional 61 

Brilliant points 106 



c 

Celluloid, Sheet of thin 5 

Center lines 60 

Cinquefoil ornament, To draw the .... 53 

Circle, Arc of a. To find the center of an 32 

Circle, Arc of a, To draw a line tangent to an 33 

Circle, To draw a right line equal to half the circumference of a 31 

Circle, To draw a tangent between two 33 

Circle, To draw tangents to two 34 

Circle, To draw an arc of a, tangent to two straight lines 34 

Circle, To inscribe a, within a triangle 35 

Circle, To draw an arc of a, tangent to two circles 36 

Circle. To draw an arc of a, tangent to a straight line and a circle 37 

Circle, To construct the involute of a 45 

Circle, To find the length of an arc of a, approximately 47 

181 



.182 INDEX, 



PAGE 



Cissoid, To draw the 49 

Compass 2 

Conventions 56 

Conventions, Shading 104 

Conventional breaks 61 

Conventional lines 60 

Conventional screw-threads 62 

Cross-sections 62 

Curves, Irregular 3 

Cycloid, To describe the 46 

D 

Dark surfaces 104 

Development of the surfaces of a hexagonal prism go 

Development of the surface of a right cylinder 92 

Development of the surface of a cone 93 

Development of the surface of a cylindrical dome 96 

Development of a locomotive gusset sheet 97 

Dihedral angles 75 

Direction, The, of the rays of light 105 

Dividers, Hair-spring 2 

Drawing-board i 

Drawing-pen ... 2 

Drawing to scale , 12, 54 



Ellipse, To describe an 38 

Ellipse, Given an, to find the axes and foci 43 

Epicycloid, To describe the 48 

Epicycloid, To describe an interior .... 50 

Equilateral triangle. To construct an 24 

Examples of working drawings 120 



Figuring and lettering 66 

Finished parts of working drawings 122 



Geometrical drawing rf^ 

Glass-paper pencil sharpener 4 

Gothic letters 69 



V 



INDEX. 183 

. H 

PAGE 

Heptagon, To construct a 28 

Hyperbola, To draw an 42 

Hypocycloid, To describe the 48 



I 

Ink eraser 4 

Inks 4 

Instruments 2 

Intersection, The, of a cylinder with a cone 93 

Intersection, The, of two cylinders 96 

Intersection, The, of a plane with an irregular surface of revolution 102 

Involute, of a circle, To construct the 45 

Isometrical cube 113 

Isometrical drawing 112 

Isometrical drawing, Direction of the rays of light in 114 

Isometrical drawing of a two-armed cross 115 

Isometrical drawing of a hollow cube 116 

Isometrical drawing, Examples of 117 

Isometrical scale. The o . . . 114 



L 

Leads for compass 13 

Lettering and figuring 64 

Line of shade 106 

Line, To draw a, parallel to another 19 

Line, To divide a 21 

Line of motion 60 

Line of section 60 



M 

Mechanical drawing and elementary machine design 122 

Model of the co-ordinate planes 81 

Moulding, The "Scotia " 51 

Moulding, The " Cyma Recta" ' 51 

Moulding, The " Cavetto " or " Hollow" 51 

Moulding, The " Echinus, " " Quatrefoil," or " Ovolo " 52 

Moulding, The "Apophygee" 52 

Moulding, The " Cyma Re versa" 52 

Moulding, The "Torus" 52 



1 84 INDEX. 

N 
Notation So 



PAGE 

T^eedies 6 



O 

Octagon, To construct an 28 

OruKtgraphic projection , 74 

Oval, To construct an 43 

P 

Paper 2 

Parabola, To construct a 41 

Pencil 2 

Pencil eraser 4 

Pencil, To sharpen the , 8 

Pen, Drawing g 

Pen, To sharpen the drawing. 10 

Pentagon, To construct a 28 

Perpendicular, To erect a 17 

Planes of projection, The , 75 

Polygon, To construct a 26 

Projection, The, of straight lines. . - 82 

Pr()j( ction, The, of plane surfaces 84 

Projection, The, of solids go 

Projection, The, of the cone. g3 

Projection of the helix as applied to screw-threads gg 

Proportional, To find a mean, to two given lines 31 

Proportional, To find a thh'd, to two given lines 3r 

Proportional. To find a fourth, to three given lines 32 

Protractor 6 

Q 

■Quatrefoil, To draw the 53 



R 

Rays of light , iq^ 

Rays, Visual J04 

Rhomboid, To construct the 21 

Right angle, To trisect a , 24 

.Roman letters 5^ 



IXDEX. 185 



S 

PAGE 

Scale guard 6 

Scale, Drawing to. ..... . 12. =4 

Scale, To construct a 5: 

Schiele's curve. To draw 50 

Screw-ihreads, Conventional 62 

Screw-thread?, Regular 100 

Section lines 56 

Section lines, Standard 5S 

Shade lines and shading 103 

Shade, To, the elevation of a sphere 108 

Shade, To, a right cylinder ico 

Shade, To, a right cone no 

Shade, To. a concave cylindrical surface no 

Shadows - IiT 

Sharpen pencij, To 3 

Sharpen pen. To lO 

Sheet brass 6 

Sheet celluloid 6 

" Sibley College " set of irregular curves 3 

" Sibley College " set o: instruments 2 

Source of liglit 104 

Spiral, To describe the 44 

Sponge rubber 5 

Square, To construct a 2^ 

Stippling , icg 



Tacks 5 

T-square 2 

Third dihedral angle 7 ; 

Tinting brush ^ 

Tinting saucer . 5 

Title, The, of a working drawing 122 

Tracing-cloth 

Trefoil, To describe the 53 

Triangles 3 

Triangle, To construct a 25 

Triangular scale. 3 

Type specimens 70 

U 

Use oi instruments ... 7 

I'se of pencil S 



iS6 INDEX. 

PAGE 

Use of drawing-pen g 

Use of triangles 1 1 

Use of T-square 1 1 

Use of drawing-board ii 

Use of scale 12 

Use of compasses . 13 

Use of dividers or spacers 13 

Use of spring bows 14 

Use of irregular curves 14 

Use of protractor 14 

V 

Visual rays 104 

Volute, To describe the " Ionic" t 45 

W 

Water-colors = . ^ . 5 

Water glass = 5 

Writing-pen 6 

Working drawings, 118 

Working drawings, Method of making iiQ 

Working drawing, What is a . • 119 

Working drawings, Examples of 1 19 



SHORT-TITLE CATALOGUE 

OF THE 

PUBLICATIONS 

OF 

JOHN WILEY & SONS, 

New York. 
LoNDOi!^: CHAPMAN & HALL, Limited, 



ARRANGED UNDER SUBJECTS. 



Descriptive circulars sent on application. Books marked ■with an asterisk (*) are sold 
at ftei prices only. All books are bound in cloth unless otherwise stated. 



AGRICULTURE— HORTICULTURE— FORESTRY. 

Armsby's Principles of Animal Nutrition 8vo, S4 00 

Budd and Hansen's American Horticultural Manual: 

Part I. Propagation, Culture, and Improvement i2mo, i 50 

Part II. Systematic Pomology i2mo, i 50 

Elliott's Engineering for Land Drainage i2mo, i 50 

Practical Farm Drainage 2d Edition, Rewritten .i2mo, 1 50 

Graves's Forest Mensuration .8vo, 4 00 

Green's Principles of American Forestry .i2mo, i 50 

Grotenfelt's Principles of Modern Dairy Practice. (WoU) i2mo, 2 00 

* Herrick's Denatured or Industrial Alcohol 8vo, 4 00 

Kemp and Waugh's Landscape Gardening. New Edition, Rewritten. (In 

Preparation.) 

* McKay and Larsen's Principles and Practice of Butter-making 8vo, i 50 

Maynard's Landscape Gardening as Applied to Home Decoration i2mo, i 50 

Quaintance and Scott's Insects and Diseases of Fruits. (In Preparation). 

Sanderson's Insects Injurious to Staple Crops i2mo, i 50 

* Schwarz's Longleaf Pine in Virgin Forests i2mo, i 25 

Stockbridge's Rocks and Soils 8vo, 2 50 

Winton's Microscopy of Vegetable Foods 8vo, 7 50 

Woll's Handbook for Fanners and Dairymen i6mo, i 50 

ARCHITECTURE. 

Baldwin's Steam Heating for Buildings i2mo, 253 

Berg's Buildings and Structures of American Railroads 4to, 5 00 

Birkmire's Architectural Iron and Steel 8vo, 3 50 

Compound Riveted Girders as Applied in Buildings 8vo, 2 00 

Planning and Construction of American Theatres 8vo, 3 00 

Planning and Construction of High Office Buildings 8vo, 3 50 

Skeleton Construction in Buildings 8vo, 3 00 

Briggs's Modern American School Buildings 8vo, 4 00 

Byrne's Inspection of Material and Wormanship Employed in Construction. 

i6mo, 3 00 

Carpenter's Heating and Ventilating of Buildings 8vo, 4 00 

* Corthell's Allowable Pressure on Deep Foundations i2mo, i 25 

1 



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Freitag's Architectura 1 Engineering 8vo 

Fireproofing of Steel Buildings 8vo, 

French and Ives's Stereotomy 8vo, 

Gerhard's Guide to Sanitary House-Inspection iCmo, 

* Modern Baths and Bath Houses Svo, 

Sanitation of Public Buildings i2mo. 

Theatre Fires and Panics i2mo, 

Hoiley and Ladd's Analysis of Mixed Paints, Color Pigments, and Varnishes 

Large i2mo, 

Johnson's Statics by Algebraic and Graphic Methods Svo, 

Kellaway's How to Lay Out Suburban Home Grounds Svo, 

Kidder's Architects' and Builders' Pocket-book i6mo, mor. 

Maire's Modern Pigments and their Vehicles i2mo, 

Merrill's Non-metallic Minerals: Their Occurrence and Uses Svo, 

Stones for Building and Decoration Svo, 

Monckton's Stair-building 4to, 

Patton's Practical Treatise on Foundations Svo, 

Peabody's Naval Architecture Svo, 

Rice's Concrete-block Manufacture Svo, 

Richey's Handbook for Superintendents of Construction i6mo, mor. 

* Building Mechanics' Ready Reference Book: 

* Building Foreman's Pocket Book and Ready Reference. (In 

Preparation.) 

* Carpenters' and Woodworkers' Edition i6mo, mor. 

* Cement Workers and Plasterer's Edition i6mo, mor. 

* Plumbers', Steam-Filters', and Tinners' Edition .... i6mo, mor. 
% Stone- and Brick-masons' Edition i6mo, mor. 

Sabin's House Painting irmo, 

Industrial and Artistic Technology of Paints and Varnish S^o, 

Siebert and Biggin's Modern Stone-cutting and Masonry Svo, 

Snow's Principal Species of Wood Svo, 

Towne's Locks and Builders' Hardware iSmo, mor. 

Wait's Engineering and Architectural Jurisprudence Svo, 

Sheep, 

Law of Contracts Svo, 

Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture - - Svo, 

Sheep, 

Wilson's Air Cond'.tioning i2mo, 

Worcester and Atkinson's Small Hospitals, Establishment and Maintenance, 
Suggestions for Hospital Architecture, with Plans for a Small Hospital. 

i2mo, I 25 

ARMY AND NAVY. 

Bernadou's Smokeless Powder, Nitro-cellulose, and the Theory of the Cellulose 

Molecule i2mo. 

Chase's Art of Pattern Making i2mo. 

Screw Propellers and Marine Propulsion Svo, 

Cloke's Enlisted Specialist's Examiner. (In Press.) 

Gunner's Examiner Svo, 

Craig's Azimuth ^to, 

Crehore and Squier's Polarizing Photo-chronograph Svo, 

* Davis's Elements of Law Svo, 

* Treatise on the Military Law of United States Svo, 

Sheep, 
De Brack's Cavalry Outpost Duties. (Carr) 24mo, mor. 

* Dudley's Military Law and the Procedure of Courts-martial.. . Large i2mo, 
Durand's Resistance and Propulsion of Ships Svo, 

2.. 





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* Dyer's Handbook of Light Artillery i2mo , 

Eissler's Modern High Explosives 8vo, 

* Fiebeger's Text-book on Field Fortification Large lamo, 

Hamilton and Bond's The Gunner's Catechism i8mo, 

* Hoff's Eleiientary Naval Tactics 8vo, 

Ingalls's Handbook of Problems in Direct Fire 8vo, 

* Lissak's Ordnance and Gunnery 8vo, 

* Ludlow's Logarithmic and Trigonometric Tables .... 8vo, 

* Lyons's Treatise on Electromagnetic Phenomena. Vols. I. and II.. 8vo, each, 

* Mahan's Permanent Fortifications. (Mercur) 8vo, half mor. 

Manual for Courts-martial i6mo, mor. 

* Mercur's Attack of Fortified Places i2mo, 

* Elements of the Art of War 8vo, 

Metcalf's Cost of Manufactures — And the Administration of Workshops. .8vo, 

Nixon's Adjutants' Manual 24mo, 

Peabody's Naval Architecture 8vo, 

* Phelps's Practical Marine Surveying 8vo, 

Putnam's Nautical Charts. (In Press.) 

Sharpe's Art of Subsisting Armies in War i8mo, mor. i 50 

* Tupes and Poole's Manual of Bayonet Exercises and Musketry Fencing. 

24mo, leather, 50 

* Weaver's Military Explosives 8vo, 3 00 

Woodhull's Notes on Military Hygiene i6mo, i 50 



ASSAYING. 

Betts's Lead Refinmg by Electrolysis , 8vo, 4 00 

Fletcher's Practical Instructions in Quantitative Assaying with the Blowpipe. 

i6mo, mor. 

Furman's Manual of Practical Assaying 8vo, 

Lodge's Notes on Assaying and Metallurgical Laboratory Experiments. . . .8vo, 

Low's Technical Methods of Ore Analysis 8vo, 

Miller's Cyanide Process i2mo, 

Manual of Assaying i2mo, 

Minet's Production of Aluminum and its Industrial Use. (Waldo) i2mo, 

O'Driscoli's Notes on the Treatment of Gold Ores 8vo, 

Ricketts and Miller's Notes on Assaying 8vo, 

Robine and Lenglen's Cyanide Industry. (Le Clerc) 8vo, 

Ulke's Modern Electrolytic Copper Refining 8vo, 

Wilson's Chlorination Process i2mo, 

Cyanide Processes i2mo, 



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Comstock's Field Astronomy for Engineers 8vo, 

Craig's Azimuth 4to, 

Crandall's Text-book on Geodesy and Least Squares 8vo, 

Doolittle's Treatise on Practical Astronomy Svo, 

Gore's Elements of Geodesy Svo, 

Hayford's Text-book of Geodetic Astronomy Svo, 

Merriman's Elements of Precise Surveying and Geodesy Svo, 

* Michie and Harlow's Practical Astronomy Svo, 

Rust's Ex-meridian Altitude, Azimuth and Star-Finding Tables. (I« Tross.) 

♦ White's Elements^f Theoretical and Descriptive Astronomy i2mo, 2 00 

3 



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CHEMISTRY. 

* Abderhalden's Physiological Chemistry in Thirty Lectures. (Hall and Defren) 

8vo, 5 oo 

* Abegg's Theory of Electrolytic Dissociation, (von Ende) i2mo, i 23 

Alexeyeff'j General Principles of Organic Syntheses. (Matthews) 8vo, 3 00 

Allen's Tables for iron Analysis 8vo, 3 00 

Arnold's Compendium of Chemistry. (Mandel) Large i2mo, 3 50 

Association of State and National Food and Dairy Departments, Hartford, 

Meeting, 1906 8vo, 3 00 

Jrinestown Meeting, 1907 8vo, 3 00 

Austen's Notes for Chemical Students i2mo, i 50 

Baskerville's Chemical Elements. (In Preparation.) 

Bernadou's Smokeless Powder. — Nitro-cellulose, and Theory of the Cellulose 

Molecule i2mo, 2 50 

* Blanchard's Synthetic Inorganic Chemistry i2mo, i c.o 

* Browning's Introduction to the Rarer Elements 8vo, i 50 

Brush and Penfield's Manual of Determinative Mineralogy 8vo, 4 00 

* Claassen's Beet-sugar Manufacture. (Hall and Rolfe) 8vo, 3 00 

Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood).. .8vo, 3 00 

Cohn's Indicators and Test-papers i2mo, 2 00 

Tests and Reagents 8vo, 3 00 

* Danneel's Electrochemistry. (Merriam) i2ino, i 25 

Duhem's Thermodynamics and Chemistry. (Burgess) 8vo, 4 00 

Eakle's Mineral Tables for the Determination of Minerals by their Physical 

Properties 8vo, i 25 

Eissler's Modern High Explosives 8vo, 4 00 

Effront's Enzymes and their AppUcations. (Prescott) 8vo, 3 00 

Erdmann's Introduction to Chemical Preparations. (Dunlap) i2mo, i 25 

* Fischer's Physiology of Alimentation Large i2mo, 2 00 

Fletcher's Practical Instructions in Quantitative Assaying with the Blowpipe. 

i2mo, mor. i 50 

Fowler's Sewage Works Analyses i2mo, 2 00 

Fresenius's Manual of Qualitative Chemical Analysis. (Wells) 8vo, 5 00 

Manual of Qualitative Chemical Analysis. Part I. Descriptive. (Weils) 8vo, 3 00 

Quantitative Chemical Analysis. (Cohn) 2 vols 8vo, 12 50 

When Sold Separately, Vol. I, $6. Vol. II, S8. 

Fuertes's Water and Public Health i2mo, i 50 

Furman's Manual of Practical Assaying 8vo, 3 00 

* Getman's Exercises in Physical Chemistry i2mo, 2 00 

GiU's Gas and Fuel Analysis for Engineers i2mo, i 25 

* Gooch and Browning's Outlines of Qualitative Chemical Analysis. 

Large i2mo, i 25 

Grotenfelt's Principles of Modern Dairy Practice. (WoU) i2mo, 2 00 

Groth's Introduction to Chemical Crystallography (Marshall) i2mo, i 25 

Hammarsten's Text-book of Physiological Chemistry. (Mandel) 8vo, 4 00 

Hanausek's Microscopy of Technical Products. Winton) 8vo, 5 00 

* Haskins and Macleod's Organic Chemistry i2mo, 2 00 

Helm's Principles of Mathematical Chemistry. (Morgan) i2mo, i 50 

Hering's Ready Reference Tables (Conversion Factors) i6mo, mor. 2 50 

* Herrick's Denatured or Industrial Alcohol 8vo, 4 00 

Hinds's Inorganic Chemistry 8vo, 3 00 

* Laboratory Manual for Students i2nio, i 00 

* HoUeman's Laboratory Manual of Organic Chemistry for Beginners. 

(Walker) i2mo, i 00 

Text-book of Inorganic Chemistry. (Cooper) 8vo, 2 50 

Text-book of Organic Chemistry. (Walker and Mott). 8vo, 2 50 

HoUey and Ladd's Analysis of Mixed Paints, Color Pigments, and Varnishes. 

Large 12 mo, 2 50 

4 



Hopkins's Oil-chemists' Handbook 8vo, 3 00 

Iddings's Rock Minerals 8vo, 5 00 

Jackson's Directions for Laboratory Work in Physiological Chemistry. .8vo, i 25 
Johannsen's Determination of Rock-forming Minerals in Thin Sections. . .Svo, 4 00 
Johnson's Chemical Analysis of Special Steels. (In Preparation.) 

Keep's Cast Iron Svo, 2 50 

Ladd's Manual of Quantitative Chemical Analysis i2mo, i 00 

Landauer's Spectrum Analysis. (Tingle) Svo, 3 oa 

* Langworthy and Austen's Occurrence of Aluminium in Vegetable Prod- 

ucts, Animal Products, and Natural "Waters Svo, L 00 

Lassar-Cohn's Application of Some General Reactions to Investigations in 

Organic Chemistry. (Tingle) i2mo, i 00 

Leach's Inspection and Analysis of Food with Special Reference to State 

Control Svo, 

Lob's Electrochemistry of Organic Compounds. (Lorenz) Svo, 

Lodge's Notes on Assaying and Metallurgical Laboratory Experiments. .. .Svo, 

Low's Technical Method of Ore Analysis Svo, 

Lunge's Techno-chemical Analysis. (Cohn)..^ i2mo, 

* McKay and Larsen's Principles and Practice of Butter-making Svo, 

Maire's Modern Pigments and their Vehicles. i2mo, 

Mandel's Handbook for Bio-chemical Laboratory i2mo, 

* Martin's Laboratory Guide to Qualitative Analysis with the Blowpipe. . i2mo. 
Mason's Examination of "Water. (Chemical and Bacteriological.). . . .i2mo. 

Water-supply. (Considered Principally from a Sanitary Stan dpi 

Svo, 
Matthews's Textile Fibres. 2d Edition, Rewritten Svo, 

* Meyer's Determination of Radicles in Carbon Compounds. (Tingle). . i2mo, 
Miller's Cyanide Process i2mo. 

Manual of Assaying i2mo, 

Minet's Production of Aluminum and its Industrial Use. (Waldo) i2mo, 

Mixter's Elementary Text-book of Chemistry i2mo, 

Morgan's Elements of Physical Chemistry i2mo. 

Outline of the Theory of Solutions and its Results i2mo, 

* Physical Chemistry for Electrical Engineers i2mo, 

Morse's Calculations used in Cane-sugar Factories i6mo, mor. 

* Muir's History of Chemical Theories and Laws Svo, 

MuUiken's General Method for the Identification of Pure Organic Compounds. 

Vol. I Large Svo, 

O'Driscoll's Notes on the Treatment of Gold Ores Svo, 

Ostwald's Conversations on Chemistry. Part One. (Ramsey) i2mo, 

Part Two. (Turnbull) i2mo, 

* Palmer's Practical Test Book of Chemistry i2mo, 

* Paull's Physical Chemistry in the Service of Medicine. (Fischer"* ... r2mo, 

* Penfield's Notes on Determinative Mineralogy and Record of Mineral Tests. 

Svo, paper, 50 
Tables of Minerals, Including the Use of Minerals and Statistics of 

Domestic Production 8vo, i 00 

Pictet's Alkaloids and their Chemical Constitution. (Biddle) Svo, 5 00 

Poole's Calorific Power of Fuels Svo, 3 00 

Prescott and Winslow's Elements of Water Bacteriology, with Special Refer- 
ence to Sanitary Water Analysis i2mo, i 50 

* Reisig's Guide to Piece-dyeing Svo, 25 00 

Richards and Woodman's Air, Water, and Food from a Sanitary Standpoint.. Svo, 2 00 

Ricketts and Miller's Notes on Assaying 8vo, 3 00 

Rideal's Disinfection and the Preservation of Food Svo, 4 00 

Sewage and the Bacterial Purification of Sewage Svo, 4 00 

Riggs's Elementary Manual for the Cliemical Laboratory Svo, i 25 

Robine and Lenglen's Cyanide Industry. (Le Clerc) Svo, 4 00 

Ruddiman's Incompatibilities in Prescriptions Svo, 2 00 

Whys in Pharmacy lamo, i 00 

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Ruer's Elements of Metallography. (Mathewson) (In Preparation.) 

Sabin's Industrial and Artistic Technology of Paints and Varnish 8vo, 

Salkowski's Physiological and Pathological Chemistry. (Orndorff) 8vo, 

Schimpf's Essentials of Volumetric Analysis i2mo, 

* Qualitative Chemical Analysis 8vo, 

Text-book of Volumetric Analysis i2mG, 

Smith's Lecture Notes on Chemistry for Dental Students , . .8vo. 

Spencer's Handbook for Cane Sugar Manvifacturers i6mo, mor, 

Handbook for Chemists of Beet-sugar Houses i6mo, mor. 

Stockbridge's Rocks and Soils 8vo, 

* Tillman's Descriptive General Chemistry .8vo, 

* Elementary Lessons in Heat 8v0j 

Treadwell's Qualitative Analysis. (HaU) , 8v0j 

Quantitative Analysis. (HaU) 8vOj 

Turneaure and Russell's Public Water-supplies 8vOi 

Van Deventer's Physical Chemistry for Beginners. (Boltwood) i2mo, 

Venable's Methods and Devices for Bacterial Treatment of Sewage 8vo, 

Ward and Whipple's Freshwater Biology. (In Press.) 

Ware's Beet-sugar Manufacture and Refining. Vol. I Small 8vo, 

Vol. 11 SmallSvo, 

Washington's Manual of the Chemical Analysis of Rocks 8vo, 

* Weaver's Mihtary Explosives 8vo, 

Wells's Laboratory Guide in Qualitative Chemical Analysis. 8vo, 

Short Course in Inorganic Quahtative Chemical Analysis for Engineering 
Students - i2mo, 

Text-book of Chemical Arithmetic i2mo, 

Whipple's Microscopy of Drinking-water 8vo, 

Wilson's Chlorination Process i2mo. 

Cyanide Processes i2mo, 

Winton's Microscopy of Vegetable Foods , . 8vo, 



CIVIL ENGINEERING. 

BRIDGES AND ROOFS. HYDRAULICS. :\L\TERIALS OF ENGINEER- 
ING. RAILWAY ENGINEERING. 

Baker's Engineers' Surveying Instruments i2mo, 

Bixby's Graphical Computing Table Paper ig^-'z/i.^ inches. 

Breed and Hosmer's Principles and Practice of Surveying. 2 Volumes. 

Vol, I. Elementary Surveying 8vo, 

Vol. II. Higher Surveying 8vo, 

* Burr's Ancient and Modem Engineering and the Isthmian Canal .... 8vo, 
Comstock's Field Astronomy for Engineers 8vo, 

* Corthell's Allowable Pressures on Deep Foundations i2mo, 

CrandaU's Text-book on Geodesy and Least Squares Svo, 

Davis's Elevation and Stadia Tables 8vo, 

Elliott's Engineering for Land Drainage i2mo, 

Practical Farm Drainage . i2mo, 

*Fiebeger's Treatise on Civil Engineering 8vo, 

Flemer's Phototopographic Methods and Instruments 8vo, 

FolweU's Sewerage. (Designing and Maintenance.) 8vo, 

Freitag's Architectural Engineering 8vo, 

French and Ives's Stereotomy 8vo, 

Goodhue's Municipal Improvements i2mo, 

Gore's Elements of Geodesy 8vo, 

* Hauch's and Rice's Tables of Quantities for Prelitcinary Estimates . . i2mo, 

Hayford's Text-book of Geodetic Astronomy 8vo, 

Bering's Ready Reference Tables. (Conversion Factors) i6mo, mor. 

Howe's Retaining Walls for Earth 12310, 

6 



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* Ives's Adjustments of the Engineer's Transit and Level i6mo, Bds. 

Ives and Hilts's Problems in Surveying i6mo, mor. 

Johnson's (J. B.) Theory and Practice of Surveying Small 8vo, 

Johnson's (L. J.) Statics by Algebraic and Graphic Methods 8vo, 

Kinnicutt, Winslow and Pratt's Purification of Sewage. (In Preparation.) 
Laplace's Philosophical Essay on Probabilities. 'Truscott and Emory) 

i2mo, 
Mahan's Descriptive Geometry 8vo, 

Treatise on Civil Engineering. (1873.) (Wood) 8vo, 

Merriman's Elements of Precise Surveying and Geodesy 8vo, 

Merriman and Brooks's Handbook for Surveyors i6mo, mor. 

Nugent's Plane Surveying 8vo, 

Ogden's Sewer Construction. (In Press.) 

Sewer Design i2mo, 

Parsons's Disposal of Municipal Refuse 8vo, 

Patton's Treatise on Civil Engineering 8vo. half leather, 

Reed's Topographical Drawing and Sketching 4to, 

Rideal's Sewage and the Bacterial Purification of Sewage 8vo, 

Riemer's Shaft-sinking under Difficult Conditions. (Coming and Peele). . . 8vo, 

Siebert and Biggin's Modern Stone-cutting and Masonry 8vo, 

Smith's Manual of Topographical Drawing. (McMillan) 8vo, 

Soper's Air and Ventilation of Subways Large i2mo, 

Tracy's Plane Surveying i6mo, mor. 

* Trautwine's Civil Engineer's Pocket-book i6mo, mor. 

Venable's Garbage Crematories in America 8vo, 

Methods and Devices for Bacterial Treatment of Sewage 8vo, 

Wait's Engineering and Architectural Jurisprudence 8vo, 

Sheep, 

Law of Contracts 8vo, 

Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture 8vo, 

Sheep, 
Warren's Stereotomy — Problems in Stone-cutting 8vo, 

* Waterbury's Vest-Pocket Hand-book of Mathematics for Engineers. 

2iX ?s inches, mor. i 00 
Webb's Problems in the Use and Adjustment of Engineering Instruments. 

i6mo, mor. i 25 

Wilson's (H. N.) Topographic Surveying 8vo. 3 

Wilson's (W. L.) Elements of Railroad Track and Construction. (In Press.) 

BRIDGES AND ROOFSo 

Boiler's Practical Treatise on the Construction of Iron Highway Bridges. .8vo. 

Burr and talk's Design and Construction of Metallic Bridges 8vo', 

Influence Lines for Bridge and Roof Computations 8vo' 

Du Bois's Mechanics of Engineering. Vol. II Sn-all 4to' 

Foster's Treatise on Wooden Trestle Bridges ,to' 

Fowler's Ordinary Foundations . c„„' 

oVO, 

French and Ives's Stereotomy o 

Greene's Arches in Wood, Iron, and Stone . . 8vo' 

Bridge Trusses 8vo' 

Roof Trusses g ' 

Grimm's Secondary Stresses in Bridge Trusses 8vo,' 

Heller's Stresses in Structures and the Accompanying Deformations ... .8vo,' 

Howe's Design of Simple Roof-trusses in Wood and Steel 8vo* 

Symmetrical Masonry Arches g' 

Treatise on Arches q„. 

Johnson, Bryan, and Turneaure's Theory and Practice in the DesipninR of 

Modern Framed Structures Small 4to. 10 00 

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Merriman and Jacoby's Text-book on Roofs and Bridges : 

Part I. Stresses in Simple Trusses 8vo, 2 50 

Part II. Grapliic Statics 8vo, 2 50 

Part III, Bridge Design 8vo, 2 50 

Part IV. Higher Structures 8vo, 2 50 

Morison's Memphis Bridge Oblong 4to, 10 00 

Sondericker's Graphic Statics, with Applications to Trusses, Beams, and Arches. 

8vo, 2 00 

Waddell's De Pontibus, Pocket-book for Bridge Engineers ..... , i6mo, mor, 2 00 

* Specifications for Steel Bridges i2mo, 50 

Waddell and Harrington's Bridge Engineering. (In Preparation.) 

Wright's Designing of Draw-spans. Two parts in one voltxme 8vo, 3 50 



HYDRAULICS. 

Barnes's Ice Formation 8vo, 3 00 

Bazin's Experiments upon the Contraction of the Liquid Vein Issuing from 

an Orifice. (Trautwine) 8vo, 

Bovey's Treatise on Hydraulics 8vo, 

Church's Diagrams of Mean Velocity of Water in Open Channels. 

Oblong 4to, paper, 

Hydraulic Motors 8vo, 

Mechanics of Engineering 8vo, 

Coffin's Graphical Solution of Hydraulic Problems i6mo, mor. 

Flather's Dynamometers, and the Measurement of Power i2mo, 

FolweU's Water-supply Engineering 8vo, 

Frizell's Water-power 8vo, 

Fuertes's Water and Public Health i2mo. 

Water-filtration Works ... i2mo, 

Ganguillet and Kutter's General Formula for the Uniform Flow of Water in 

Rivers and Other Channels. CHering and Trautwine, 8vo, 

Hazen's Clean Water and How to Get Tt Large i2mo, 

Filtration of Public Water-suppl'es 8vo, 

Hazlehurst's Towers and Tanks for Water- works 8vo, 

Herschel's 115 Experiments on the Carrying Capacity of Large, Riveted, Metal 

Conduits 8vo, 

Hoyt and Grover's River Discharge 8vo, 

Hubbard and Kiersted's Water- works Management and Maintenance 8vo, 

^ Lyndon's Development and Electrical Distribution of V/a'er "Power. . . .8vo, 
Mason's Water-supply. (Considered Principally from a Sanitary Standpoint.) 

8vo, 
Merriman's Treatise on Hydraulics 8vo, 

* Michie's Elements of Analytical Mechanics Svo, 

* Molitor's Hydraulics of Rivers. Wefrs and Pluiceo . . fi.vo, 

Schuyler's Reservoirs for Irrigation, Water-power, and Domestic Water- 
supply Large 8vo, 

* Thoma" and Watt's Improvement of Rivers 4to, 

Turneaure and Russell's Public Water-supplies Svo, 

Wegmann's Design and Construction of Dams. 5th Ed., enlarged . . . 4to, 

Water-supply of the City of New York from 1658 to 1895 4to, 

Whipple's Value of Pure Water Large ismo, 

Williams and Hazen's Hydraulic Tables Svo, 

Wilson's Irrigation Engineering Small Svo, 

Wolff's Windmill as a Prime Mover Svo, 

Wood's Elements of Analytical Mechanics Svo, 

Turbines 8vo, 

8 



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MATERIALS OF ENGINEERING. 

Baker's Roads and Pavements 8vo, 

Treatise on Masonry Construction. ..,, 8vo. 

Birkmire'sj Architectural Iron and Steel Svo, 

Compound Riveted Girders as Applied in Buildings Svo, 

Black's United States Public Works Oblong 4:0, 

Bleininger's Manufacture of Hydraulic Cement. (In Preparation ) 

* Bovey's Strength of Materials and Theory of Structures Svo, 

Burr's Elasticity and Resistance of the Materials of Engineering Svo, 

Byrne's Highway Construction Svo, 

Inspection of the Materials and Workmanship Employed in Construction. 

i6mo, 

Church's Mechanics of Engineering Svo, 

Du Bois's Mechanics of Engineering. 

Vol. I. Kinematics, Statics, Kinetics Small 4to, 7 50 

Vol. II. The Stresses in Framed Structures, Strength of Materials and 

Theory of Flexures Email 4to, 

♦Eckel's Cements, Limes, and Plasters Svo, 

Stone and Clay Products used in Engineering. (In Preparation.) 

Fowler's Ordinary Foundations Svo, 

Graves's Forest Mensuration Svo, 

Green's Principles of American Forestry lamo, 

* Greene's Structural Mechanics Svo, 

Holly and Ladd's Analysis of Mixed Paints, Color Pigments and Varnishes 

Large rzmo, 2 50 
Johnson's (C. M.) Chemical Analysis of Special Steels. (In Preparation.) 

Johnson's (J. B.) Materials of Construction Large Svo, 

Keep's Cast Iron Svo, 

Kidder's Architects and Builders* Pocket-book i6mo, 

Lanza's Applied Mechanics Svo, 

Maire's Modern Pigments and their Vehicles . . lamo, 

Martens's Handbook on Testing Materials. (Henning) 2 vols Svo, 

Maurer's Technical Mechanics Svo, 

Merrill's Stones for Building and Decoration Svo, 

Merriman's Mechanics of Materials Svo, 

* Strength of Materials i2mo, 

Metcalf's Steel. A Manual for Steel-users. . i2mo, 

Morrison's Highway Engineering Svo, 

Patton's Practical Treatise on Foundations Svo, 

Rice's Concrete Block Manufacture Svo, 

Richardson's Modern Asphalt Pavements Svo. 

Richey's Handbook for Superintendents of Construction lOmo, mor. 

* Ries's Clays: Their Occurrence, Properties, and Uses Svo, 

Sabin's Industrial and Artistic Technology of Paints ard Varnish Svo, 

*Schwarz'sLonffleafPinein Virgin Forest I^JHO' 

Snow's Principal Species of Wood ^^°' 

Spalding's Hydraulic Cement '2"^°' 

Text-book on Roads and Pavements "ino, 

Taylor and Thompson's Treatise on Concrete, Plain and Reinforced Svo, 

Thurston's Materials of Engineering. In Three Parts Svo. 

Part I. Non-metallic Materials of Engineering and Metallurgy 8vo, 

Part IT. Iron and Steel ^^^• 

Part III. A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents ^^^* 

Tilbcn*s Street Pavements and Paving Materials 8vo. 

Tumeaure and Maurer's Principles of Reinforced Concrete Construction .Svo. 
Waterbury's Manual of Instructions ior the Use of Students in Cement Labora- 
tory Practice. (In Press.) 





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Wood's (De V.) Treatise on the Resistance of Materials, and an Appendix on 

the Preservation of Timber 8vo, 2 00 

Wood's (M. P.) Rustless Coatings: Corrosion and Electrolysis of Iron and 

Steel Svo, 4 00 

RAILWAY ENGINEERING. 

Andrews's Handbook for Street Railway Engineers 3x5 inches, mor. i 25 

Berg*s Buildings and Structures of American Railroads .'. .4to, 5 00 

Brooks's Handbook of Street Railroad Location i6mo, mor. i 50 

Butt's Civil Engineer's Field-book i6rao, mor. 2 50 

Crandall's Railway and Other Earthwork Tables Svo. i 50 

Transition Curve i6mo, mor. i 50 

* Crockett's Methods for Earthwork Computations Svo, i 50 

Dawson's "Engineering" and Electric Traction Pocket-book. ..... i6mOr mor. 5 00 

Dredge's History of the Pennsylvania Railroad: (1879) Paper, 5 00 

Fisher's Table of Cubic Yards Cardboard, 23 

Godwin's Railroad Engineers' Field-book and Explorers' Guide. . . i6mo, mor. 2 50 
Hudson's Tables for Calculating the Cubic Contents of Excavations and Em- 
bankments Svo, I 00 

Ives and Hilts's Problems in Surveying, Railroad Surveying and Geodesy 

i6mo, mor. i 50 

Molitor and Beard's Manual for Resident Engineers i6mo, i 00 

Nagle's Field Manual for Railroad Engineers i6mo, mor. 3 00 

Philbrick's Field Manual for Engineers. i6mo, mor. 3 00 

Raymond's Railroad Engineering. 3 volumes. 

Vol. I. Railroad Field Geometry. (In Preparation.) 

Vol. XL Elements of Railroad Engineering. Svo, 3 50 

Vol. III. Railroad Engineer's Field Book. (In Preparation.) 

Searles's Field Engineering i6mo, mor. 3 00 

Railroad Spiral i6mo, mor. i 50 

Taylor's Prismoidal Formulae and Earthwork Svo, i 50 

*Trautwine's Field Practice of Laying Out Circular Curves for Railroads. 

i2mo. mor. 2 50 

* Method of Calculating the Cubic Contents of Excavations and Embank- 

ments by the Aid of Diagrams. . Svo, 2 00 

Webb's Economics of Railroad Construction Large i2mo, 2 50 

Railroad Construction i6mo, mor. 5 00 

Wellington's Economic Theory of the Location of Railways Small Svo, 5 00 

DRAWING. 

Barr's Kinematics of Machinery Svo, 2 50 

* Bartlett's Mechanical Drawing Svo, 3 00 

* " " •' Abridged Ed Svo, 150 

Coolidge's Manual of Drawing Svo, paper, i 00 

Coolidge and Freeman's Elements of General Drafting for Mechanical Engi- 
neers Oblong 4to, 2 50 

Durley's Kinematics of Machines Svo, 4 00 

Emch's Introduction to Projective Geometry and its Applications Svo, 2 50 

Hill's Text-book on Shades and Shadows, and Perspective Svo, 2 00 

Jamison's Advanced Mechanical Drawing Svo, 2 00 

Elements of Mechanical Drawing Svo, 2 50 

Jones's Machine Design: 

Part I. Kinematics of Machinery, Svo, i 30 

Part II, Form, Strength, and Proportions of Parts Svo, 3 00 

MacCord's Elements of Descriptive Geometry Svo, 3 oc 

Kinematics ; or, Practical Mechanism Svo, 5 00 

Mechanical Drawing 4to, 4 00 

Velocity Diagrams. ... Svo, i 50 

10 



McLeod's Descriptive Geometry Large i2mo, 

* Mahan's Descriptive Geometry and Stone-cutting 8vo, 

Industrial Drawing. (Thompson ) 8vo, 

Meyer's Descriptive Geometry 8vo, 

Reed's Topographical Drawing and Sketching 4to, 

Reid's Course in Mechanical Drawing 8vo, 

Text-book of Mechanical Drawing and Elementary Machine Design. 8vo, 

Robinson's Principles of Mechanism 8vo, 

Schwamb and Merrill's Elements of Mechanism 8vo, 

Smith's (R. S.) Manual of Topographical Drawing. (McMillan) 8vo, 

Smith (A. W.) and Marx's Machine Design. . .^ .8vo, 

* Titsworth's Elements of Mechanical Drawing. Oblong 8vo, 

Warren's Drafting Instruments and Operations i2mo, 

Elements of Descriptive Geometry, Shadows, and Perspective 8vo, 

Elements of Machine Construction and Drawing 8vo, 

Elements of Plane and Solid Free-hand Geometrical Drawing i2mo, 

General Problems of Shades and Shadows 8vo, 

Manual of Elementary Problems in the Linear Perspective of Form and 

Shadow i2mo, 

Manual of Elementary Projection Drawing i2mo, 

Plane Problems in Elementary Geometry i2mo, 

Problems, Theorems, and Examples in Descriptive Geometry 8vo, 

Weisbach's Kinematics and Power of Transmission. (Hermann and 
Klein) 8vo, 

Wilson's (H. M.) Topographic Surveying 8yo, 

Wilson's (V. T.) Free-hand Lettering 8vo, 

Free-hand Perspective 8vo, 

Woolf's Elementary Course in Descriptive Geometry. Large 8vo, 

ELECTRICITY ^AND PHYSICS. 

* Abegg's Theory of Electrolytic Dissociation, (von Ende) i2mo, 

Andrews's Hand-Book for Street Railway Engineering ... .3 X 5 inches, mor. 

Anthony and Brackett's Text-book of Physics. (Magie).. •. Large i2mo, 

Anthony's Lecture-notes on the Theory of Electrical Measurements. . . .i2mo, 
Benjamin's History of Electricity 8vo, 

Voltaic Cell 8vo, 

Betts's Lead Refining and Electrolysis 8vo, 

Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood). .8vo, 

* Collins's Manual of Wireless Telegraphy i2mo, 

Mor. 
Crehore and Squier's Polarizing Photo-chronograph 8vo, 

* Danneel's Electrochemistry. (Merriam) i2mo, 

Dawson's "Engineering" and Electric Traction Pocket-book .... i6mo, mor. 

Dolezalek's Theory of the Lead Accumulator (Storage Battery), (von Ende) 

i2mo, 

Duhem's Thermodynamics and Chemistry. (Burgess) Svo, 

Flather's Dynamometers, and the Measurement of Power i2mo, 

Gilbert's De Magnete. (Mottelay) Svo, 

* Hanchett's Alternating Currents i2mo, 

Bering's Ready Reference Tables (Conversion Factors') i6mo, mor. 

* Hobart and Ellis's High-speed Dynamo Electric Machinery 8vo, 

Holman's Precision of Measurements 8vo, 

Telescopic Mirror-scale Method, Adjustments, and Tests. . . .Large Svo, 

* Karapetoff' s Experimental Electrical Engineering Svo, 

Kinzbrunner's Testing of Continuous-current Machines Svo, 

Landauer's Spectrum Analysis. (Tingle) Svo, 

Le Chatelier's High-temperature Measurements. (Boudouard — Burgess).. 1 2mo, 
L()b's Electrochemistry of Organic Compounds, (Lorenz) Svo, 

* London's Development and Electrical Distribntion of Water Tower Svo, 

11 



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* Lyons's Treatise on Electromagnetic Phenomena. Vols. I. and II. 8vo, each, 

* Michie's Elements of "Wave Motion Relating to Sound and Light 8vo, 

Morgan's Outline of the Theory of Solution and its Results i2mo, 

* Physical Chemistry for Electrical Engineers i2mo, 

Niaudet's Elementary Treatise on Electric Batteries. (Fishback). . . .i2mo, 

* Korris's Introduction to the Study of Electrical Engineering 8vo, 

* Parshall and Hobart's Electric Machine Design 4to, half mor. 

Reagan's Locomotives: Simple, Compound, and Electric. New Edition. 

Large 12 mo, 

* Rosenberg's Electrical Engineering. (Haldane Gee — Kinzbrunner). .. .Svo, 

Ryan, Norris, and Hoxie's Electrical Machinery. Vol. I Svo, 

S^happer's Laboratory Guide for Students in Physical Chemistry i2mo, 

* Tillman's Elementary Lessons in Heat Svo, 

Tory and Pitcher's Manual of Laboratory Physics Large i2mo, 

Ulke's Modern Electrolytic Copper Refining c ^. Svo, 

LAW. 

* Davis's Elements ot Law Svo, 

* Treatise on the Military Law of United States Svo, 

* Sheep, 

* Dudley's Military Law and the Procedure of Courts-martial . . . .Large i2nio, 

Manual for Courts-martial i6mo, mor. 

Wait's Engineering and Architectural Jurisprudence Svo, 

Sheep, 

Law of Contracts Svo, 

Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture Svo 

Sheep, 

MATHElVfATICS. 

Baker's Elliptic Functions Svo, 

Briggs's Elements of Plane Analytic Geometry. (Bocher) . .i2mo, 

* Buchanan's Plane and Spherical Trigonometry Svo, 

Byerley's Harmonic Functions Svo, 

Chandler's Elements of the Infinitesimal Calculus i2mo, 

Compton's Manual of Logarithmic Computations i2mo, 

* Dickson's College Algebra Large i2mo, 

* Introduction to the Theory of Algebraic Equations Large i2mo, 

Emch's Introduction to Projective Geometry and its Applications Svo, 

Fiske's Functions of a Complex Variable Svo, 

Halsted's Elementary Synthetic Geometry Svo, 

Elements of Geometry Svo, 

* Rational Geometry i2mo, 

Hyde's Grassmann's Space Analysis , Svo, 

* Jonnson's {J- B,) Three-place Logarithmic Tables: Vest-pocket size, paper, 

100 copies, 

* Mounted on heavy cardboard, S X 10 inches, 

10 copies, 
Johnson's (W. W.) Abridged Editions of Differential and J-ite^ral Calculus 

Large i2mOj i vol. 

Curve Tracing in Cartesian Co-ordinates i2mo. 

Differential Equations Svo, 

Elementary Treatise on Differential Calculus Large i2mo, 

Elementary Treatise on the Integral Calculus Large i2mo, 

* Theoretical Mechanics i2mo. 

Theory of Errors and the Method of Least Squares i2mo. 

Treatise on Differential Calculus Large i2mo. 

Treatise on the Integral Calculus Large i2mo, 

Treatise on Ordinary and Partial Differential Equations. . Large i2mo, 

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Laplace's Philosophical Essay on Probabilities. (Truscott and Emory). .i2mo, 2 00 

* Ludlow and Bass's Elements of Trigonometry and Logarithmic and Other 

Tables 8vo, 3 00 

Trigonometry and Tables published separately Each, 2 00 

* Ludlow's Logarithmic and Trigonometric Tables 8vo, i 00 

Macfarlane's Vector Analysis and Quaternions 8vo, i 00 

McMahon's Hyperbolic Functions 8vo, i 00 

Manning's Irrational lumbers and their Representation by Sequences and 

Series i2mo, i 25 

Mathematical Monographs. Edited by Mansfield Merriman and Robert 

S. Woodward. Octavo, each i 00 

No. I. History of Modern Mathematics, by David Eugene Smith. 
No. 2. Synttietic Projective Geometry, by George Bruce Halsted. 
No. 3. Determinants, by Laenas Gifford Weld. No. 4. Hyper- 
bolic Functions, by James McMahon. Fo, 5. Harmonic Func- 
tions, by William E. Byerly. No. 6. Grassmann's Space Analysis, 
by Edward W, Hyde. No. 7. Probability and Theory of Errors, 
by Robert S. Woodward. No. 8. Vector Analysis and Quaternions, 
by Alexander Macfarlane. No. 9. Differential Equations, by 
William Woolsey Johnson. No. 10. The Solution of Equations, 
by Mansfield Merriman. No. 11. Functions of a Complex Variable, 
by Thomas S. Fiske. 

Maurer'a Technical Mechanics 8vo, 

Merriman's Method of Least Squares 8vo, 

Solution of Equations 8vo, 

Rice and Johnson's Differential and Integral Calculus. 2 vols, in one. 

Large i2mo, 

Elementary Treatise on the Differential Calculus Large i2mo. 

Smith's History of Modern Mathematics 8vo, 

* Veblen and Lennes's Introduction to the Real Infinitesimal Analysis of One 

Variable 8vo, 2 00 

* Waterbury's Vest Pocket Hand-Book of Mathematics for Engine rs. 

2s XSs inches, mor. i 00 

Weld's Determinations 8vo, i co 

Wood's Elements of Co-ordinate Geometry 8vo, 2 00 

Woodward's Probability and Theory of Errors 8vo, i oo 



MECHANICAL ENGINEERING. 
MATERIALS OF ENGINEERING, STEAM-ENGINES AND BOILERS. 

Bacon's Forge Practice i2mo, i 50 

Baldwin's Steam Heating for Buildings i2mo, 2 50 

Bair's Kinematics of Machinery 8vo, 2 50 

* Bartlett's Mechanical Drawing 8vo, 3 00 

* " " " Abridged Ed 8vo, 150 

Benjamin's Wrinkles and Recipes i2mo, 2 00 

* Burr's Ancient and Modern Engineering and the Isthmian Canal 8vo, 3 50 

Carpenter's Experimental Engineering 8vo, 6 00 

Heating and Ventilating Buildings 8vo, 4 00 

Clerk's Gas and Oil Engine Larpie i2mo, 4 00 

Compton's First I^essons in Metal Working izmo, i 50 

Compton and De Groodt's Speed Lathe i2mo, i 50 

Coolidge's Manual of Drawing 8vo, paper, i 00 

Coolidge and Freeman's Elements of General Drafting for Mechanical En- 
gineers Oblong 4to, 2 50 

Cromwell's Treatise on Belts and Pulleys 1 2mo, i 50 

Treatise on Toothed Gearing i2mo, 1 50 

Durley's Kinematics of Machines 8vo, 4 00 

13 



Flather's Dynamometers and the Measurement of Power- lamo, 

Rope Driving I2mc, 

Gill's Gas and Fuel Analysis for Engineers i2mo, 

Goss'-, Locomotive Sparks 8vo, 

Greene's Pumping Machinery. (In Preparation.) 

Bering's Ready Reference Tables (Conversion Factors) ... i6mo, mor. 

* Hobart and Ellis's High Speed Dynamo Electric Machinery 8vo. 

Button's Gas Engine 8vo, 

Jamison's Advanced Mechanical Drawing Bvo, 

Elements of Mechanical Drawing 8vo, 

Jones's Machine Design: 

Part I. Kinematics of Machinery 8vo, 

Part n. Form, Strength, and Proportions of Parts 8vo, 

Kent's Mechanical Engineers' Pocket-book i6mo, mor. 

Kerr's Power and Power Transmission 8vo, 

Leonard's Machine Shop Tools and Methods' 8vo, 

* Lorenz's Modern Refrigerating Machinery. (Pope, Haven, and Dean) . . . 8vo, 
MacCord's Kinematics; or, Practical Mechanism 8vo, 

Mechanical Drawing. 4to, 

Velocity Diagrams 8vo, 

MacFar land's Standard Reduction Factors for Gases 8vo, 

Mahan's Industrial Drawing. (Thompson) 8vo, 

* Parshall and Hobart's Electric Machine Design Small 4to, half leather, 

Peele's Compressed Air Plant for Mines 8vo, 

Poole's Calorific Power of Fuels 8vo, 

* Porter's Engineering Reminiscences, 1855 to 1882 8vo, 

Reid's Course in Mechanical Drawing 8vo, 

Text-book of Mechanical Drawing and Elementary Machine Design. 8vo, 

Richard's Compressed Air i2mo, 

Robinson's Principles of Mechanism 8v6, 

Schwamb and Merrill's Elements of Mechanism 8vo, 

Smith's (O.) Press-working of Metals 8vo, 

Smith (A. W.) and Marx's Machine Design 8vo, 

Sore! ' s Carbureting and Combustion in Alcohol Engines . (Woodward and Preston) . 

Large 12 mo, 3 00 

Thurston's Animal as a Machine and Prime Motor, and the Laws of Energetics. 

i2mo, I 00 

Treatise on Friction and Lost Work in Machinery and Mill Work... 8vo, 3 00 

Tillson's Complete Automobile Instructor i6mo, i 50 

mor. 2 00 

* Titsworth's Elements of Mechanical Drawing Oblong 8vo, i 25 

Warren's Elements of Machine Construction and Drawing 8vo, 7 50 

* Waterbury's Vest Pocket Hand Book of Mathematics for Engineers. 

28 Xsf inches, mor. i 00 

Weisbach's Kinematics and the Power of Transmission. (Herrmann — 

Klein) 8vo, 5 00 

Machinery of Transmission and Governors. (Herrmann — Klein).. .8vo, 5 00 

Wood's Turbines. , 8vo, 2 50 

MATERIALS OF ENGINEERING. 

* Bovey's Strength of Materials and Theory of Structures 8vo, 

Burr's Elasticity and Resistance of the Materials of Engineering 8vo, 

Church's Mechanics of Engineering 8vo, 

* Greene's Structural Mechanics 8vo, 

HoUey and Ladd's Analysis of Mixed Paints, Color Pigments, and Varnishes. 

Large i2mo, 

Johnson's Materials of Construction „ 8vo, 

Keep's Cast Iron 8vo, 

Lanza's Applied Mechanics 8voj 

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Maire's Modern Pigments and their Vehicles i2mo, 2 00 

Martens's Handbook on Testing Materials. (Henning) 8vo, 7 50 

Maurer's Technical Mechanics 8vo, 4 00 

Merriman's Mechanics of Materials 8vo, 5 00 

* Strength of Materials i2mo, i 00 

Metcalf's Steel. A Manual for Steel-users i2mo, 2 00 

Sabin's Industrial and Artistic Technology of Paints and Varnish 8vo, 3 00 

Smith's Materials of Machines i2mo, i 00 

Thurston's Materials of Engineering 3 vols., 8vo, 8 00 

Part I. Non-metallic Materials of Engineering and Metallurgy . . .8vo, 2 00 

Part II. Iron and Steel 8vo, 3 50 

Part III. A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents 8vo, 2 50 

Wood's (De V.) Elements of Analytical Mechanics 8vo, 3 00 

Treatise on the Resistance of Materials and an Appendix on the 

Preservation of Timber 8vo, 2 00 

Wood's (M. P.) Rustless Coatings: Corrosion and Electrolysis of Iron and 

Steel 8vo, 4 00 



STEAM-ENGINES AND BOILERS. 

Berry's Temperature-entropy Diagram i2mo, i 25 

Carnot's Reflections on the Motive Power of Heat. (Thurston) '. .i2mo, i 50 

Chase's Art of Pattern Making i2mo, 2 50 

Creighton's Steam-engine and other Heat-motors 8vo, 5 00 

Dawson's "Engineering" and Electric Traction Pocket-book i6mo, mor. 5 00 

Ford's Boiler Making for Boiler Makers. . i8mo, i 00 

Gebhardt's Steam Power Plant Engineering. (In Press.) 

Goss's Locomotive Performance 8vo, 5 00 

Hemenway's Indicator Practice and Steam-engine Economy i2mo, 2 00 

Button's Heat and Heat-engines 8vo, 5 00 

Mechanical Engineering of Power Plants 8vo, 5 00 

Kent's Steam boiler Economy 8vo, 4 00 

Kneass's Practice and Theory of the Injector 8vo, i 50 

MacCord's Slide-valves Svo, 2 00 

Meyer's Modern Locomotive Construction 4to, 10 oc 

Moyer's Steam Turbines. (Tn Press.) 

Peabody's Manual of the Steam-engine Indicator i2mo. i 50 

Tables of the Properties of Saturated Steam and Other Vapors Svo, i 00 

Thermodynamics of the Steam-engine and Other Heat-engines Svo, s 00 

Valve-gears for Steam-engines Svo, 2 50 

Peabody and Miller's Steam-boilers 8vo, 4 00 

Pray's Twenty Years with the Indicator Large Svo, 2 5c 

Pupin's Thermodynamics of Reversible Cycles in Gases and Saturated Vapors. 

(Osterberg) i2mo, i 25 

Reagan's Locomotives: Simple, Compound, and Electric. New Edition. 

Large 12 mo. 3 50 

Sinclair's Locomotive Engine Running and Management 12 mo, 2 00 

Smart's Handbook of Engineering Laboratory Practice 12 mo, 2 50 

Snow's Steam-boiler Practice Svo, 3 00 

Spangler's Notes on Thermodynamics i2mo, i 00 

Valve-gears Svo, 2 50 

Spangler, Greene, and Marshall's Elements o Steam-engineering Svo, 3 00 

Thomas's Steam-turbines Svo, 4 00 

Thurston's Handbook o' Engine and Boiler Trials, and the Use of the Indi- 
cator and the Prony Brake Svo, 5 00 

Handy Tables Svo, 1 50 

Manual of Steam-boilers, their resigns. Construction, and Operation. .Svo, 5 00 

15 



Thurston's Manual of the Steam-engine 2 vols., 8vo, 10 00 

Part I. History, Structure, and Theory 8vo, 6 00 

Fart II. Design, Construction, and Operation 8vo, 6 00 

Steam-boiler Explosions in Theory and in Practice i2nio, i 50 

Wehrenfenning's Analysis and Softening of Boiler Feed-water (Patterson) 8vo, 4 00 

Weisbach's Heat, Steam, and Steam-engines. (Du Bois) Bvo, 5 00 

Whitham's Steam-engine Design Bvo, 5 00 

Wood's Thermodynamics, Heat Motors, and Refrigerating Machines. . .Svo, 4 00 

MECHANICS PURE AND APPLIED. 

Church's Mechanics of Engineering Svo, 6 00 

Notes and Examples in Mechanics Svo, 2 00 

Dana's Text-book of Elementary Mechanics for Colleges and Schools. .i2mo, i 50 
Du Bois's Elementary Principles of Mechanics: 

Vol. I. Kinematics Svo, 3 50 

Vol. II. Statics Svo, 4 00 

Mechanics of Engineering. Vol. I Small 4to, 7 50 

VoL II. Small 4to, 10 00 

♦•Greene's Structural Mechanics Svo, 2 50 

James's Kinematics of a Point and the Rational Mechanics of a Particle. 

Large i2mo, 2 00 

* Johnson's (W. W.) Theoretical Mechanics i2mo, 3 00 

Lanza's Applied Mechanics Svo, 7 50 

* Martin's Text Book on Mechanics, Vol. I, Statics i2mo, i 25 

* Vol. 2, Kinematics and Kinetics . .i2mo, l 50 
Maurer's Technical Mechanics Svo, 4 00 

* Merriman's Elements of Mechanics i2mo, i 00 

Mechanics of Materials Svo, 5 00 

* Michie's Elements of Analytical Mechanics : Svo, 4 00 

Robinson's Principles of Mechanism Svo, 3 00 

Sanborn's Mechanics Problems Large i2mo, i 50 

Scnwamb and Merrill's Elements of Mechanism Svo, 3 00 

Wood's Elements of Analjrtical Mechanics Cvo, 3 00 

Principles of Elementary Mechanics ' i2mo, i 25 

MEDICAL. 

* Abderhalden's Physiological Chemistry in Thirty Lectures, (^all and Defren) 

Svo, 
von Behring's Suppression of Tuberculosis. (Bolduan) i2mo, 

* Bolduan's Immune Sera i2nio,' 

Davenport's Statis-ical Methods with Special Reference to Biological Varia- 
tions i6mo, mor. 

Ehrlich's Collected Studies on Immunity. (Bolduan) Svo, 

* Fischer's Physiology of Ahmentation Large i2mo, cloth, 

de Fursac's Manual of PsychJatry. (Rosanoff and Collins) Large i2mo, 

Hammarsten's Text-book on Physiological Chemistry. (Mandel) Svo, 

Jackson's Directions for Laboratory Work in Physiological Chemistry. ..Svo, 

Lassar-Cohn's Practical Urinary Analysis. (Lorenz) i2mo, 

Mandel's Hand Book for the Bic-Chemical Laboratory i2mo, 

* Pauli's Physical Chemistry in the Service of Medicine. (Fischer) i2mo, 

* Pozzi-Escot's Toxins and Venoms and their Antibodies. (Cohn) i2mo, 

Rostoski's Serum Diagnosis. (Bolduan) i2mo, 

Ruddiman's Incompatibilities in Prescriptions , 8vo, 

Whys in Pharmacy i2mo, 

Salkowski's Physiological and Pathological Chemistry. (Orndorff) Svo, 

* Satterlee's Outlines of Human Embryology i2mo, 

Smith's Lecture Notes on Chemistry for Dental Students 8vo. 

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Steel's Treatise on the Diseases of the Dog 8vo, 3 50 

* Whipple's Typhoid Fever Large i2mo, 3 00 

Woodhull's Notes on Military Hygiene i6mo, i 50 

* Personal Hygiene i2mo, i 00 

Worcester and Atkinson's Small Hospitals Establishment and Maintenance, 

and S ggestions for Hospital Architecture, with Plans for a Small 

Hospital lamo, i 25 

METALLURGY. 

Betts's Lead Refining by Electrolysis 8vo, 4 00 

BoUand's Encyclopedia of Founding and Dictionary of Foundry Terms Used 

in the Practice of Moulding lamo, 

Iron Founder i2mo, 

" " Supplement i2mo, 

Douglas's Untechnical Addresses on Technical Subjects. . : i2mo, 

Goesel's Minerals and Metals: A Reference Book i6mo, mor. 

* Iles's Lead-smelting i2mo, 

Keep's Cast Iron gvo, 

Le Chatelier's High-temperature Measurements. (Boudouard — Burgess) i2mo, 

Metcalf"? Steel. A Manual for Steel-users i2mo, 

Miller's Cyanide Process i2mo, 

Minet's Production of Aluminium and its industrial Use. (Waldo) . . .i2mo, 

Robipe and Lenglen's Cyanide Industry. (Le Clerci 8vo, 

Ruer's Elements of Metallography. (Mathewson) (In Press.) 

Smith'c Materials of Machines i2mo, 

Thurston's Materials of Engineering. In Three Parts Bvo, 

Part I. Non-metallic Materials of Engineering and Metallurgy . . . Svo, 

Part II. Iron and Steel Svo, 

Part III. A Treatise on Erfsses, Bronzes, and Other Alloys and their 

Constituents Svo, 

Ulke's Modern Electrolytic Copper'Refining .* Svo, 

West's American Foundry Practice i2mo. 

Moulder's Text Book i2mo, 

Wilson's Chlorination Process i2mo, 

Cyanide Processes i amo, 

MINERALOGY. 

Barringer's Descripti'^n of Minerals of Commercial Value Oblong, mor. 2 50 

Boyd's Resources of Southwest Virginia Svo, 3 00 

Boyd's Map of Southwest Virginia. Pocket-book form. 2 00 

* Brownin<;'s Introduction to the Rarer Elements Svo, i 50 

Brush's Manual of Determinative Mineralogy. (Penfield) Svo, 4 00 

Butler's Pocket Hand-Book of Minerals i6mo, mor. 3 00 

Chester's Catalogue of Minerals Svo, paper, i 00 

Cloth, I 25 

* Crane's Gold and Silver Svo, 5 00 

Dana's First Appendix to Dana's New " System of Mineralogy. .". .Large Svo, i 00 

Manual of Mineralogy ard Petrography i::mo 2 00 

Minerals and How to Study Them i2mo, i 50 

System of Mineralogy Large Bvo, half leather, 12 50 

Text-book of Mineralogy 8vo, 4 00 

Pouglas's Untechnical Addresses on Technical Subjects i2mo, i 00 

Ea'Kle's Mineral Tables 8vo, i 25 

Stone and Clay Products Used in Engineering. (In Preparation.) 

E' leston's Catalogue of Minerals and Synonyms Svo, 2 50 

Goesel's Minerals and Metals: A Reference Book i6mo,mor. 300 

Groth's Introduction to Chemical Ctystallography (Marshall) lamo, i 25 

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* Iddings's Rock Minerals 8vo, 

Johannsen's Determination of Rock-forming Minerals in Thin Sections 8vo, 

* Martin's Laboratory Guide to Qualitative Analysis with the Blowpipe. i2mo, 
Merrill's Non-metallic Minerals: Their Occurrence and Uses 8vo, 

Stones for Building and Decoration 8vo, 

* Penfield's Notes on Determinative Mineralogy and Record of Mineral Tests. 

8vo, paper, 50 

Tables of Minerals, Including the Use of Minerals and Statistics of 

Domestic Production 8vo, i 00 

* Pirsson's Rocks and Rock Minerals i2mo, 2 50 

* Richards's Synopsis of Mineral Characters.^ I2mo, mor. i 25 

* Ries's Clays: Their Occurrence, Properties, and Uses 8vo, 5 00 

* Tillman's Text-book of Important Minerals and Rocks 8vo, 2 00 

MINING. 

* Beard's Mine Gases and Explosions Large i2mo, 

Boyd's Map of Southwest Virginia Pocket-book form. 

Resources of Southwest Virginia 8vo, 

* Crane's Gold and Silver 8vo, 

Douglas's Untechnical Addresses on Technical Subjects i2mo. 

Eissler's Modern High Explosives 8vo, 

Goesel's Minerals and Metals: A Reference Book. . , i6mo, mor. 

Ihlseng's Manual of Mining 8vo, 

* lies's Lead-smelting i2mo, 

Miller's Cyanide Process « i2mo, 

O'DriscoU's Notes on the Treatment of Gold Ores 8vo, 

Peele's Compressed Air Plant for Mines 8vo, 

Riemer ' s Shaft Sinking Under Difficult Conditions . ( Coming and Peele) . . . 8vo , 
Robine and Lenglen's Cyanide Industry. (Le Clerc) 8vo, 

* Weaver's Military Explosives 8vo, 

Wilson's Chlorination Process i2mo, 

Cyanide Processes i2mo, 

Hydraulic and Placer Mining. 2d edition, rewritten I2m0s 

Treatise on Prapctical and Theoretical Mine Ventilation "i2mo, 

SANITARY SCIENCE. 

Association of State and National Food and Dairy Departments, Hartford Meeting, 

1906 8vo, 

Jamestown Meeting, 1907 8vo, 

• * Bashore's Outlines of Practical Sanitation i2mo, 

Sanitation of a Country House i2mo, 

Sanitation of Recreation Camps and Parks i2mo, 

Folwell's Sewerage. (Designing, Construction, and Maintenance) 8vo, 

Water-supply Engineering 8vo, 

Fowler's Sewage Works Analyses i2mo, 

Fuertes's Water-filtration Works .' i2mo, 

Water and Public Health i2mo, 

Gerhard's Guide to Sanitary House-inspection , i6mo, 

* Modem Baths and Bath Houses 8vo, 

Sanitation of Public Buildings i2mo, 

Hazen's Glean Water and How to Get It Large i2mo. 

Filtration of Public Water-supplies 8vo, 

Kinnicut, Winslow and Pratt's Purification of Sewage. (In Press.) 

Leach's Inspection and Analysis of Food with Special Reference to State 

Control 8vo, 

Mason's Examination of Water. (Chemical and Bacteriological) i2mo, 

Water-supply. (ConsideredPrincipaUyfrom a Sanitary Standpoint). .8vo, 

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* Merriman's Elements of Sanitary Engineering 8vo, 

Ogden's Sewer Design i2mo, 

Parsons 's Disposal of Municipal Refuse 8vo, 

Prescott and Winslow's Elements of Water Bacteriology, with Special Refer- 
ence to Sanitary Water Analysis i2mo, 

* Price's Handbook on Sanitation i2mo 

Richards's Cost of Food. A Study in Dietaries 12 mo. 

Cost of Living as Modified by Sanitary Science i2mo, 

Cost of Shelter 1 2mo, 

* Richards and Williams's Dietary Computer 8vo, 

Richards and Woodman's Air, Water, and Food from a Sanita-y Stand- 
point 8vo, 

Rideal's Disinfection and the Preservation of Food 8vo, 

Sewage and Bacterial Purification of Sewage 8vo, 

Sopor's Air and Ventilation of Subways . Large i2mo, 

Turneaure and Russell's Public Water-supplies Svo, 

Venable's Garbage Crematories in America Svo, 

Method and Devices for Bacterial Treatment of Sewage Svo, 

Ward and Whipple's Freshwater Biology. (In Press. ) 

Whipple's Microscopy of Drinking-water 8vo, 

* Tyrhod Fever Large i2mo, 

Value of Pure Water Large i2mo, 

Winslow's Bacterial Classification, dn Press.) 

Winton's Microscopy of Vegetable Foods 8 vo, 7 50 

MISCELLANEOUS. 

Emmons's Geological Guide-book of the Rocky Mountain Excursion cf the 

International Congress of Geologists Larf a Svo, i 50 

Ferrel's Popular Treatise on the Winds Svo, 4 00 

Fitzgerald's Boston Machinist i8mo, i 00 

Gannett's Statistical Abstract of the World 24mo, 75 

Haines's American Railway Management i2mo, 2 50 

* Hanusek's The Microscopy of Technical Products. (Winton) Svo, 5 00 

Ricketts's History of Rensselaer Polytechnic Institute 1824-1894. 

Large 12 mo, 3 00 

Rotherham's Emphasized New Testament , Large Svo, 2 00 

Standage's Decoration of Wood, Glass, Metal, etc i2mo, 2 00 

Thome's Structural and Physiological Botany. (Bennett). .* i6mo, 2 25 

Westermaier's Compendium of General Botany. (Schneider) 8vo, 2 00 

Winslow's Elements of Applied Microscopy 12 m, j 50 



HEBREW AND CHALDEE TEXT-BOOKS. 

Green's Elementary Hebrew Grammar 1 2mo, i 25 

Gesenius's Hebrew and Chaldee Lexicon to the Old Testament Scr'ptures. 

(Tregelles) Small 4to. half mor. 5 00 

19 



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